1、 Guide for Propulsion Systems for LNG Carriers GUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS SEPTEMBER 2005 (Updated February 2014 see next page) American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 Copyright 2005 American Bureau of Shipping ABS Plaza 16855 No
2、rthchase Drive Houston, TX 77060 USA Updates February 2014 consolidation includes: July 2013 version plus Corrigenda/Editorials July 2013 consolidation includes: February 2011 version plus Notice No. 2 February 2011 consolidation includes: December 2005 version plus Notice No. 1 December 2005 consol
3、idation includes: September 2005 version plus Corrigenda/Editorials ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 iii Foreword Foreword (1 February 2011) Every LNG carrier, in service at the time of the issuance of this Guide, has been fitted with a steam turbine powered propulsion plant. H
4、owever, recently, many owners and shipyards, looking to improve operational efficiency and reduce the size of the engine room to increase cargo carrying capacity have selected propulsion plants alternatives to steam turbine There are various proposed machinery arrangements being considered by the in
5、dustry which include: Direct drive slow speed diesel engine propulsion with a reliquefaction plant as the means to dispose of the boil-off gas. Direct drive slow speed dual fuel diesel engine(s) propulsion. Electric propulsion with medium speed dual fuel diesel engines Electric propulsion with dual
6、fuel gas turbine(s) as the prime mover(s). In some cases, with the combination of propulsion and power generation alternatives mentioned above, there may be a need to also install a gas combustion unit to dispose of excess boil-off gas. It must be acknowledged that while the IMO IGC Code permits the
7、se various arrangements as acceptable means for pressure/temperature control in the cargo tanks, it does not comprehensively address propulsion systems other than steam turbine. Accordingly, this Guide has been developed in order to provide guidance for the design and construction of aforementioned
8、propulsion solutions with particular attention to the safe utilization of boil-off gas. The requirements in this Guide are consistent with the intent of the requirements of the IGC Code and have been developed by extensive use of the risk based rule-making methodology, i.e., risk identification by a
9、 group of specialists and stipulation as to the means of mitigation of the risks identified. In all cases the requirements of this Guide is to supplement areas which are not addressed in the IGC Code and is not intended to conflict or replace any of the requirements in the IGC Code. Where the requir
10、ements of this Guide are proposed to be used to comply with Chapter 16.6 of the IGC Code, such application is subject to approval by the flag Administration prior to issuance of Certificate of Fitness on behalf of the flag Administration by ABS. This Guide has been developed for the propulsion syste
11、m for LNG carriers. However, the Guide may be applied to other types of vessels that utilize methane as fuel. This Guide supersedes the ABS Guide for Design and Installation of Dual Fuel Engines, January 2003. The applicable edition of the Rules for Building and Classing Steel Vessels is to be used
12、in association with the subject Guide. This Guide becomes effective immediately upon publication. We welcome your feedback. Comments or suggestions can be sent electronically to rddeagle.org. iv ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 Table of Contents GUIDE FOR PROPULSION SYSTEMS FOR
13、 LNG CARRIERS CONTENTS SECTION 1 General 1 1 Definitions . 1 1.1 BOG Utilization System . 1 1.2 Dual Fuel Diesel Engine 1 1.3 Re-Liquefaction Unit 1 1.4 Gas Combustion Unit (or Thermal Oxidizer) 1 1.5 Dual Fuel Propulsion or Auxiliary Gas Turbine 1 1.6 Normal Boil-off Gas Rate (NBOR) . 1 1.7 Rules .
14、 1 1.8 MARVS 1 2 Operating and Maintenance Instruction Manuals . 2 SECTION 2 Notations . 3 1 Re-Liquefaction Unit . 3 2 Gas Combustion Unit 3 3 Dual Fuel Diesel Engine Power Plant . 3 4 Dual Fuel Gas Turbine Power Plant . 3 SECTION 3 Boil-off Gas Utilization . 4 1 Utilization or Disposal of Boil-off
15、 Gas . 4 1.1 BOG Utilization Arrangement 4 2 Supply of BOG to Utilization Units 4 2.1 Automatic Gas Shut-off Valve 4 2.2 Automatic Purge 4 2.3 Master Gas Valve 5 2.4 Pressure Surge Protection . 5 SECTION 4 Re-liquefaction Unit 6 1 General . 6 1.1 Capacity . 6 1.2 LNG Return to Cargo Tanks 6 1.3 Plan
16、s and Data to be Submitted 6 ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 v 2 Cargo Vapor (BOG)/LNG Circuit 7 2.1 BOG Compressors 7 2.2 LNG Pumps . 7 2.3 Separation of Impurities. 7 3 Refrigeration System 7 3.1 General 7 3.2 Refrigerants . 7 3.3 Compressors/Expanders . 8 3.4 Cryogenic Heat
17、 Exchangers and Cold Box . 8 4 Instrumentation and Safety Systems 9 4.1 General 9 4.2 Control and Monitoring System . 9 4.3 Safety Shutdown System 9 5 Electrical System 10 5.1 Motor Controllers . 10 6 Location and Installation . 10 7 Mechanical Ventilation 10 8 Gas Detection System 10 9 Ancillary Sy
18、stems 10 10 Piping System . 11 11 Fire Extinguishing Systems. 11 12 Surveys During Construction 11 12.1 General 11 12.2 Surveys at Manufacturers Facility . 12 12.3 Surveys During Installation 12 12.4 Surveys During Trials 13 TABLE 1 Instrumentation and Alarms in Centralized Control Stations . 13 TAB
19、LE 2 Certification of Re-Liquefaction Units . 14 SECTION 5 Gas Combustion Units/Thermal Oxidizers . 15 1 General . 15 1.1 Capacity 15 1.2 Plans and Data to be Submitted 15 2 Cargo Vapor (BOG) Circuit . 16 2.1 Compressors . 16 2.2 Heaters 16 2.3 Gas Fuel Supply to GCU . 16 3 Gas Burner Unit and Burne
20、r Management System 17 4 Oil Pilot Burner/Electrical Ignition System 17 5 Forced Draft Fans and Dilution Fans 17 6 Combustion Chamber and Associated Refractory . 18 7 Exhaust Gas Piping 18 8 Ventilation . 18 9 Gas Detection . 19 vi ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 10 Automatic
21、Shutdown System 19 11 Fire Extinguishing System 19 12 Surveys During Construction 20 12.1 General 20 12.2 Surveys at Manufacturers Facility . 20 12.3 Surveys During Installation 20 12.4 Surveys During Trials 21 TABLE 1 Instrumentation and Alarms in Centralized Control Stations for the GCU . 21 TABLE
22、 2 Certification of Gas Combustion Units 22 SECTION 6 Dual Fuel Diesel Engines Propulsion System . 23 1 General . 23 1.1 Condition . 23 1.2 Application . 23 1.3 Plans and Data to be Submitted 23 2 Arrangement of Dual Fuel Engine Compartments with Single Wall Fuel Gas Piping 24 2.1 General 24 2.2 Ven
23、tilation 24 2.3 Gas Detection 25 2.4 Electrical Equipment 25 2.5 Access and Means of Escape . 26 3 Gas Fuel Supply for Arrangements with Single Wall Fuel Gas Piping 26 3.1 Piping System up to Engine Compartment 26 3.2 Block and Bleed Valves . 26 3.3 Gas Shut-off Valve . 26 3.4 Manual Shut Off . 26 3
24、.5 Piping System in Engine Compartment . 26 3.6 Purging 27 3.7 Restoration of Gas Fuel Supply . 27 4 Gas Make-up Plant and Related Storage Tanks 27 5 Dual Fuel Engines . 27 5.1 General 27 5.2 Gas Fuel and Air Supply 27 5.3 Protection of Crankcase 28 5.4 Protection against Explosion . 28 5.5 Engine E
25、xhaust System . 29 5.6 Cooling Water Expansion Tank . 29 6 Emergency Shutdown . 29 6.1 Automatic Shut Off of Gas Fuel Supply . 29 6.2 Emergency Shutdown of the Dual Fuel Engine Compartment . 30 6.3 Power Management . 30 ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 vii 7 Surveys During Cons
26、truction 30 7.1 General 30 7.2 Surveys at Manufacturers Facility . 30 7.3 Surveys During Installation 31 7.4 Surveys During Trials 31 TABLE 1 Monitoring and Safety System Functions for Dual Fuel Diesel Engines 29 TABLE 2 Monitoring and Safety System Functions for Gas Fuel Supply Systems 30 TABLE 3 C
27、ertification of Dual Fuel Diesel Engines . 32 SECTION 7 Dual Fuel Gas Turbine Propulsion System 33 1 General . 33 1.1 Application . 33 2 Arrangement of Dual Fuel Gas Turbines 33 2.1 General 33 3 General . 34 3.1 Gas Turbine Propulsion System 34 4 Plans and Data to be Submitted . 34 5 Materials of Co
28、nstruction 35 6 Dual Fuel Propulsion Gas Turbines 35 6.1 General 35 6.2 Gas Fuel Manifold . 36 6.3 Gas Fuel Control Valves 36 7 Gas Turbine Enclosure . 36 7.1 General 36 7.2 Construction 36 8 Enclosure Air Intakes and Exhaust System 37 8.1 General 37 8.2 Combustion Air Intake System 39 8.3 Exhaust S
29、ystem 40 9 Gas Turbine Enclosure Ventilation . 41 9.1 General 41 9.2 System Requirements . 41 10 Fire and Gas Detection . 42 10.1 Gas Detection System Requirements . 42 10.2 Gas Detection Set Point 42 10.3 Installation . 42 10.4 Periodic Maintenance and Testing 42 11 Fire Protection and Fire Extingu
30、ishing System . 43 11.1 General 43 11.2 Fixed Fire Extinguishing Systems . 43 11.3 Portable Foam Applicators, Dry Material and Portable Fire Extinguishers . 43 11.4 Fixed Local Application Firefighting Systems 43 11.5 Fire Detection System Requirements 43 viii ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG
31、 CARRIERS .2005 12 Piping and Auxiliary Systems 43 12.1 General 43 12.2 Gas Fuel Supply Piping System to Gas Turbine 43 12.3 Block and Bleed Valve Arrangement . 44 12.4 Gas Shut-off Valve . 44 12.5 Gas Compressor 44 12.6 Pressure Vessels, Heat Exchangers and Coolers . 44 12.7 Exhaust Gas Boilers 44
32、12.8 In-duct Burner 44 13 Electrical, Automation, Instrumentation and Control Systems 45 13.1 General 45 13.2 Electrical Equipment 45 13.3 Alarm and Shutdown System 45 14 Surveys During Construction 45 14.1 General 45 14.2 Surveys at Manufacturers Facility . 45 14.3 Surveys During Installation 46 14
33、.4 Surveys During Trials 46 TABLE 1 Monitoring and Safety System Functions for Dual Fuel Gas Turbine Engines and Supply Systems 47 TABLE 2 Certification of Dual Fuel Gas Turbines 47 SECTION 8 Surveys After Construction and Maintenance of Class 49 1 General . 49 1.1 Definitions 49 1.2 Damage, Failure
34、 and Repair 49 1.3 Modifications 50 2 Survey Intervals 50 2.1 Annual Survey . 50 2.2 Intermediate Survey . 50 2.3 Special Periodical Survey 50 2.4 Continuous Survey Program 50 2.5 Survey Based upon Preventative Maintenance Techniques 50 3 Surveys . 51 4 Alternative Surveys . 51 4.1 Inspection Plan 5
35、1 4.2 Application . 51 APPENDIX 1 Certification of Pressure Vessels . 52 TABLE 1 Certification of Pressure Vessels 52 ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 1 Section 1: General SECTION 1 General This Guide has been developed to provide guidance for the design, construction and surve
36、y of systems and arrangements provided for the propulsion system and for the safe utilization of boil-off gas on LNG carriers. 1 Definitions 1.1 BOG Utilization System A BOG (boil-off gas) utilization system is an arrangement of BOG consumers (e.g., dual fuel diesel engines, dual fuel gas turbine(s)
37、, re-liquefaction units or gas combustion unit(s), including piping systems, electrical systems, control and safety systems, which are intended for controlling cargo tank pressure and maintaining it below the maximum allowable relief valve setting. 1.2 Dual Fuel Diesel Engine Dual Fuel Diesel Engine
38、s are diesel engines using BOG as fuel and also having the capability of running on liquid fuel. 1.3 Re-Liquefaction Unit A Re-liquefaction Unit is a system used for taking the boil-off gas from cargo tanks and condensing it in a refrigeration system. LNG is then returned to the cargo tanks. A typic
39、al re-liquefaction plant will comprise an electric motor-driven boil-off gas compressor, cryogenic heat exchangers, pre-coolers, separator, nitrogen storage tanks, an LNG transfer system, electric-driven refrigeration compressors/expanders with interstage coolers, a discharge cooler and associated c
40、ontrol systems. 1.4 Gas Combustion Unit (or Thermal Oxidizer) A Gas Combustion Unit (or Thermal Oxidizer) is a system used for controlling the pressure in the cargo tanks by burning the excess boil-off gas from the cargo tanks inside an enclosed combustion chamber under controlled and safe condition
41、s. 1.5 Dual Fuel Propulsion or Auxiliary Gas Turbine Dual Fuel Gas Turbine, Propulsion or Auxiliary is a gas turbine using boil-off gas as fuel and also having the capability of running on liquid fuel. 1.6 Normal Boil-off Gas Rate (NBOR) For the purposes of this Guide, the Normal Boil-off Rate is th
42、e specified BOR in the shipbuilding contract, conforming to the design boil-off rate at the conditions as specified in the IGC code. 1.7 Rules The applicable edition of the ABS Rules for Building and Classing Steel Vessels (Steel Vessel Rules). 1.8 MARVS Maximum allowable relief valve setting. Secti
43、on 1 General 2 ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 2 Operating and Maintenance Instruction Manuals Detailed instruction manuals are to be provided onboard, covering the operations, safety and maintenance requirements and occupational health hazards relevant to the use of gas as a
44、fuel. The manuals are to include, but not be limited to, the test procedure for the gas detection system, safety shut-off system and the integrity of backup systems, with special attention given to the periodical maintenance procedures for the gas detection system. The manuals are to be submitted fo
45、r review solely to ensure the presence of all the information required by this Section. ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 3 Section 2: Notations SECTION 2 Notations 1 Re-Liquefaction Unit Where a Re-Liquefaction Unit is designed, constructed and tested in accordance with Section
46、s 3 and 4 of this Guide, the RELIQ notation will be assigned. 2 Gas Combustion Unit Where a Gas Combustion Unit is designed, constructed and tested in accordance with Sections 3 and 5 of this Guide, the GCU notation will be assigned. 3 Dual Fuel Diesel Engine Power Plant Where a dual fuel diesel eng
47、ine power plant is designed, constructed and tested in accordance with Sections 3 and 6 of this Guide, the DFD notation will be assigned. 4 Dual Fuel Gas Turbine Power Plant Where a dual fuel gas turbine power plant is designed, constructed and tested in accordance with Sections 3 and 7 of this Guid
48、e, the DFGT notation will be assigned. 4 ABSGUIDE FOR PROPULSION SYSTEMS FOR LNG CARRIERS .2005 Section 3: Boil- off Gas Utilization SECTION 3 Boil-off Gas Utilization 1 Utilization or Disposal of Boil-off Gas 1.1 BOG Utilization Arrangement Unless the entire cargo system is designed to withstand th
49、e full gauge vapor pressure of the cargo under conditions of the upper ambient design temperatures, as specified in 5C-8-7/1.2 of the Steel Vessel Rules, means are to be provided to maintain the cargo tank pressure below the MARVS by safely utilizing or disposing of the natural LNG boil-off at all times, including while in port, while maneuvering or standing by, as per Section 5C-8-7 of the Steel Vessel Rules. Systems and arrangements that may be provided for this purpose may include one or any combination of the following: i) A steam boiler with a common propulsion
