A DESIGN TOOL FOR THE EVALUATION OF ATMOSPHERE INDEPENDENT PROPULSION IN SUBMARINES by Grant B. Thomton, LCDR, USN B.S., Marine Engineering United States Naval Academy, 1979 SUBMITTED TO THE DEPARTMENTS OF OCEAN ENGINEERING AND MECHANICAL ENGINEERING IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREES OF MASTER OF SCIENCE IN NAVAL ARCHITECTURE AND MARINE ENGINEERING and MASTER OF SCIENCE IN MECHANICAL ENGINEERING at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 1994 Copyright © 1994 Grant B. Thomton The author hereby grants to MIT permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole or in part. Signatureof Author . ... -- .,/../ ~-u-_:.-.;Departments of Ocean and Mechanical Engineering May 6, 1994 Certified by Professor David Gordon Wilson Thesis Reader - . Department of Mechanical Engineering Accepted b!y "-----' PrfessA. DouglasCarmichael Thesis Advisor and Chairma0, Jepartment Committee on Graduate Students ,W1IT;.- ;,:^.-- . Department of Ocean Engineering ~:'~!'JUNi":~2 i'"'-1994 JUN 2 0 1994 Lonn_;:> (Blank Reverse) 2 A DESIGN TOOL FOR THE EVALUATION OF ATMOSPHERE INDEPENDENT PROPULSION IN SUBMARINES by Grant Blount Thornton Submitted to the Departments of Ocean Engineering and Mechanical Engineering on May 6, 1994 in partial fulfilment of the requirements for the Degrees of Master of Science in Naval Architecture and Marine Engineering and Master of Science in Mechanical Engineering. ABSTRACT For the United States Navy, submarine propulsion has long since evolved from Diesel Electric to a complete reliance on Nuclear Power. Nuclear propulsion is the ultimate atmosphere independent power source, allowing the submarine to divorce itself from the surface, limited only by the endurance of the crew embarked. Submarine construction and operating costs have grown dramatically, due largely to the cost of the high performance nuclear propulsion plant. Other options exist to provide Atmosphere Independent Propulsion of similar capability for extended underwater periods at a potentially lower cost. This thesis explores the aspects of non-nuclear atmosphere independent propulsion as an integral part of the submarine design process, focusing on methods for power generation and various options for fuel and oxidant storage. Fuel sources include pure hydrogen, stored cryogenically or in metal hydrides, or more common fuels such as diesel or methanol, used either directly or in a reformed state. Oxidants include pure oxygen, stored cryogenically or in compressed form, as well as hydrogen peroxide and sodium perchlorate. Energy conversion methods examined include mechanical such as closed cycle diesels, Brayton cycles and Stirling engines, to electro-chemical designs, such as fuel cells and aluminum oxygen semi- cells. A computer code was written which integrates these propulsion options with mission and owner's requirements to provide a balanced design in terms of matching the weights and volumes of the equipment installed. This code will serve as a tool for the concept design of non-nuclear air independent submarines. Thesis Supervisor: A. Douglas Carmichael, Professor of Ocean Engineering Thesis Reader: David Gordon Wilson, Professor of Mechanical Engineering 3 (Blank Reverse) 4 ACKNOWLEDGEMENTS I wish to acknowledge the following persons who aided me in my search for reference material: Dave Bagley NSWC Annapolis Mark Cervi NSWC Annapolis Henry DeRonck International Fuel Cells LCDR Norbert Doerry NAVSEA Richard Martin Draper Laboratory Warren Reid NSWC Annapolis Ed Robinson NAVSEA PEO SUB-R Steve Sinsabaugh LORAL Defense Industries LT Cliff Whitcomb NSWC Carderock I hope that I have correctly interpreted the information that you made available to me. I am grateful for the counsel in ship and submarine design provided by Professors Alan Brown and Jeff Reed in the Naval Construction and Engineering Program at MIT. I wish to thank my Thesis Advisor, Professor A. D. Carmichael who inspired me to investigate the realm of Air Independent Propulsion as a student, who stood by me as I worked to put my research together in an orderly fashion, and who taught me to be aware of the salesman and the customer when evaluating data. But most of all, I am thankful for the love and understanding of my family; Daryl, David and Megan, as I complete my studies at MIT. 5 (Blank Reverse) 6 TABLE OF CONTENTS ABSTRACT 3 ACKNOWLEDGEMENTS 5 TABLE OF CONTENTS 7 LIST OF FIGURES . 13 LIST OF TABLES 17 CHAPTER ONE 1.0 Introduction 19 1.1 History 19 1.2 Air Independence Concept 20 1.3 Propulsion Options 21 1.4 Thesis Objective 21 CHAPTER TWO 2.0 The Design Process 25 2.1 Mission Requirements. 27 2.2 Required Operational Capabilities 29 2.3 Submarine Hull Synthesis 33 CHAPTER THREE 3.0 Submarine Systems 37 3.1 Propulsion Integration . 38 3.1.1 Conventional DC 38 3.1.2 Permanent Magnet AC 40 3.1.3 Superconducting Homopolar DC 42 3.1.4 Propulsors 44 3.2 Ship Service Power Requirements 44 3.3 Auxiliary Systems 46 3.4 Atmosphere Control 46 CHAPTER FOUR 4.0 Power Sources . 51 4.1 Electro-Chemical Concepts 52 4.1.1 Fuel Cells 52 4.1.1.1 Proton Exch. Membrane Fuel Cells 54 4.1.1.2 Alkaline Fuel Cells 57 4.1.1.3 Phosphoric Acid Fuel Cells 57 4.1.1.4 Molten Carbonate Fuel Cell 58 4.1.1.5 Solid Oxide Fuel Cell 60 4.1.1.6 Direct Methanol Oxidation Fuel Cell 60 4.1.2 Aluminum Oxygen Semi-Cell 62 4.1.3 Batteries 64 4.1.3.1 Lead Acid Batteries 65 4.1 .3.2 Nickel-Cadmium Batteries 68 7 (Blank Reverse) 8 4.1.3.3 Silver-Zinc . .70 4.1.3.4 Lithium-Aliminum / Iron Sulfide 72 4.2 Mechanical Power Sources 74 4.2.1 Closed Cycle Engines 74 4.2.1.1 Closed Cycle Diesel 74 4.2.1.2 Closed Brayton Cycle 77 4.2.2 Stirling Engine 79 4.2.3 Other Power Cycles. .. 80 4.2.3.1 Rankine Cycle 81 4.2.3.2 Small Nuclear Power 83 4.2.3.3 Walter Cycle 83 CHAPTER FIVE 5.0 Reactants 87 5.1 Fuels 88 5.1.1 Hydrogen 88 5.1.1.1 Hydrogen - Gaseous Storage 89 5.1.1.2 Hydrogen - Cryogenic Storage 89 5.1.1.3 Hydrogen - Metal Hydride 90 5.1.1.4 Hydrogen - By Reformation 92 5.1.2 Other Fuels 94 5.2 Oxidants. 95 5.2.1 Oxygen 95 5.2.1.1 Oxygen - Gaseous Storage 95 5.2.1.2 Oxygen - Cryogenic Storage 96 5.2.1.3 Oxygen - Chemical Reformation. 98 5.2.1.4 Oxygen - Generation Onboard . 99 5.2.2 High Test Hydrogen Peroxide 99 5.3 Waste Products 101 CHAPTER SIX 6.0 The Submarine Model. 105 6.1 Hull Envelope . 106 6.2 Volume Estimates 107 6.2.1 Pressure Hull Volume 107 6.2.1.1 Mobility Volume 107 6.2.1.2 Weapons and C31 Volume 108 6.2.1.3 Ship Support Volume 108 6.2.2 Other Volumes 109 6.3 Weight Estimates 110 6.3.1 Surfaced Displacement 111 6.3.1.1 Structural Weight . 111 6.3.1.2 Mobility Weight 111 6.3.1.3 Weapons and C31Weight 112 6.3.1.4 Ship Support Weight 112 6.3.1.5 Fixed Ballast and Variable Load Wt 113 9 (Blank Reverse) 10 6.4 Powering and Edurance 114 6.4.1 Powering 114 6.4.1.1 Hydrodynamics 114 6.4.1.2 Propulsion Motor Turndown 117 6.4.2 Snort Power and Bunker Fuel Calculation 117 6.4.3 Hotel Loads 118 6.4.4 Battery Endurance 119 6.5 The AIP Plant 120 CHAPTER SEVEN 7.0 Computer Code Development 121 7.1 Overview 121 CHAPTER EIGHT 8.0 Results and Conclusions 125 8.1 Model Validation 125 8.2 General Results 127 8.2.1 Overall AIP Impact 128 8.2.2 Impact of Reactants . 130 8.2.3 Impact of Other Technologies 132 8.3 Ship Trade-offs. 135 CHAPTER NINE 9.0 Areas for Future Study 139 REFERENCES 141 APPENDIX A - POWER SOURCE DOCUMENTATION 147 APPENDIX B - REACTANT DOCUMENTATION 163 APPENDIX C - BASELINE MODEL 175 APPENDIX D - HULL ENVELOPE 191 APPENDIX E - VOLUME DATA BASE 195 APPENDIX F - WEIGHT DATA BASE 201 APPENDIX G - SNORKEL POWERING 205 APPENDIX H - RESULT DATA TABLES. 207 APPENDIX I - COMPUTER CODE 211 11 (Blank Reverse) 12 LIST OF FIGURES 2.1 Acquisition Milestones and Phases 26 2.2 The Design Spiral . 27 2.3 Balancing Weights and Volumes . 35 3.1 Battery Stepping Operating Modes for a Double Armature DC Mtr 39 3.2 Permanent Magnet Axial Gap Propulsion Motor 40 3.3 Permanent Magnet High Speed Generator 41 3.4 Example of Chopped AC Output from Input DC. 42 3.5 Superconducting Homopolar DC Motor . 43 3.6 Typical Ship Service Distribution System 45 3.7 Hydraulic System with Typical Loads 47 3.8 High Pressure Air System . 47 3.9 Ventilation Arrangement 49 4.1 Efficiency vs. Load for AIP Options 53 4.2 Proton Exchange Membrane Fuel Cell 55 4.3 PEM Cell Voltage vs. Cell Load 56 4.4 Molten Carbonate Fuel Cell 59 4.5 Westinghouse Solid Oxide Fuel Cell 61 4.6 Aluminum Oxygen Semi-Cell 63 4.7 Lead Acid Battery Schematic 67 4.8 Typical Lead Acid Discharge Characteristics 67 4.9 Nickel-Cadmium Discharge Characteristics 70 4.10 Silver Zinc Discharge Characteristics 72 4.11 LAIS Battery Discharge Characteristics . 74 4.12 Closed Cycle Diesel with Exhaust Management System 76 4.13 Closed Brayton Cycle Combustion Power System 78 4.14 Closed Brayton Cycle Schematic Flow Diagram 79 4.15 Stirling Operating Cycle 81 4.16 MESMA Operating Cycle . 82 4.17 AMPS Power Cycle.