SINAVY PEM Fuel Cell For submarines Marine & Shipbuilding Answers for industry. Introduction page 3 PEM Fuel Cell: function and design page 6 PEM Fuel Cell: 2 modules and power plant page 8 Outlook page 11 Fuel cells enable the direct generation of electric power from hydrogen and oxygen with significantly higher efficiency, with noiseless operation and without pollutant emissions compared with conventional combustion engines. 3 Application potential Decentral power plants Freighter Grid-independent operation (SOFC, PEM FC) Emergency power supply (PEM FC) Reformer gas/air Submarine H2/O2 Bus H2/air Air-independent propulsion (PEM FC) Emission-free and noiseless operation (PEM FC) Space shuttle Delivery trucks Fuel Cell power plants Present and future applications Air-independent power supply (PEM FC) Emission-free and noiseless operation (PEM FC) Storage system for regenerative energies Passenger car Siemens Electrolyzer (PEM FC) Emission-free and energy-­ efficient operation (PEM FC) Reformer gas/air 4 Railroad Gas tanker Electrical propulsion (SOFC, PEM FC) Electrical propulsion (SOFC, PEM FC) Fig. 1: Possible applications for fuel cell power plants In addition to these basic advantages, the fuel cell with a solid, ion-conducting, polymeric membrane (polymer electrolyte membrane – PEM) has more positive properties: ◾◾ Quick switch-on, switch-off behavior ◾◾ Low voltage degradation and long service life ◾◾ Favorable load and temperature-cycle behavior ◾◾ Capability of overload operation ◾◾ Low operating temperature (80° Celsius) ◾◾ Absence of a liquid-corrosive electrolyte. All of these characteristics make the SINAVY PEM Fuel Cell an ideal power unit. Aboard submarines they show their outstanding ­advantages over other AIP (air-independent propulsion) systems for conventional submarines. Using oxygen and hydrogen stored in liquid or gaseous form on board as reactants, the only process result besides electricity and small amounts of residual gases which are given into the boats atmosphere is process water which could be used for different purposes – such as weight balancing to avoid process-related needs for trim adaptions of the submarine. Siemens has two types of SINAVY PEM Fuel Cell modules for you to choose from. The FCM 34, with a rated power of 34 kW, and the FCM 120, with a rated power of 120 kW. Submarines of Class U 212 A (six in the German Navy and four in the Italian Navy) are equipped with FCM 34 modules, which were developed from 1985 at the request of the German Ministry of Defense. Submarines of Class 214 and Class 209 PN – in the Hellenic Navy, Republic of Korea Navy, Portuguese Navy, and Turkish Navy – are equipped with FCM 120 modules, which were Energy Hydrogen Oxygen Water Fig. 2 developed in a later phase. Development work on the third-generation ­module (FCM NG) has recently started. The rated power of FCM NG is flexible in the range between 80 and 160 kW. Operational submarines of Class 209 can be upgraded with an additional fuel-cell power plant during refit, and so acquire the benefits of air-independent propulsion (AIP) at a much lower price than for acquiring a new submarine. The suitability of fuel-cell technology on board submarines has been demonstrated by earlier tests and more recently on submarines of classes U 212 A, 214, and ­Dolphin AIP. 5 PEM Fuel Cell: function and design A simplified representation of the SINAVY PEM Fuel Cells' basic function and design is shown in (Fig. 3): the ­electrochemical element at which the chemical energy is converted into electrical energy is the membrane ­electrode unit. It consists of the polymer electrolyte, the gas diffusion electrodes with a platinum catalyst and carbon sheets on each side. After the abstraction of the electrons from hydrogen – they flow from the anode via the electrical load to the cathode – the resulting protons migrate from the anode to the cathode where they combine with oxygen (and the electrons) to form water. The theoretical voltage of an H2/O2 fuel cell is 1.48 V (referred to the upper heat value of hydrogen). At ­zero-load conditions, slightly more than one volt per cell is available. The cooling units or bipolar plates, in combination with carbon diffusion layers, distribute the reactants ­uniformly across the area of the cell, conduct the 6 ­ lectrons across the stack, remove the heat from the e electrodes, and separate the media from each other. Figure 4 shows the two core components of a cell with outside dimensions of 400 x 400 mm, as used in FCM 34 modules. Figure 5 compares the bipolar plate of the FCM 34 modules to the FCM 120 and the FCM NG. Two cells of the FCM 120 produce about twice the power of one cell of the FCM 34 type with nearly the same active area. The theoretically high development potential in regard to the membrane material is shown in Figure 6. With improved materials, the power density can be nearly doubled. The voltage of a SINAVY PEM Fuel Cell with respect to the operating time is stable, and degradation rates are less than 2 µV/h per cell for FCM 34 module. Significantly lower values were achieved during the operation of a FCM 120. This module went through different operational conditions (Fig. 7). Electrical load 4e⁻ Hydrogen H2 Oxygen O2 H⁺ 2H2 + 4e⁻ = 4H⁺ O2 + 4e⁻ = 20⁻ 20⁻ + 4H⁺ = 2H2O H⁺ Waste H⁺ Anode Cathode Product water H 2O + O 2 Polymer electrolyte Fig. 3: Functional principle Cooling unit 400 mm Membrane electrode unit Cooling unit 224 220 Naf 115 200 0.6 Naf 117 0 500 1000 0 1500 216 Load Profile / 75 °C 212 208 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Current I/A Fig. 6: Potential output increases by using various electrolytes Start–Stop Operation / 75 °C 400 0.7 0.5 232 228 Start–Stop Operation / 70 °C / 70 % VKW 0.8 236 Constant Load at 390 A / 70 °C 600 Start–Stop Operation / 75 °C 0.9 800 244 240 Load Profile / 70 °C Naf 117 248 Start–Stop Operation / 70 °C 1.0 1000 FAT's Naf 115 Constant Load at 560 A / 70 °C 1.1 Module Voltage [V] Fig. 5: Comparison of cells: FCM NG Type (back), FCM 34 Type (center), FCM 120 Type (front) Cell Output PC/W Cell Voltage [UC/V] Fig. 4: Components of cell Operational Hours [h] Fig. 7: FCM 120 / Module Voltage at 560 A and 390 A 7 PEM Fuel Cell: modules and power plant PEM Fuel Cell modules Siemens has put every effort into integrating the PEM Fuel Cell stack, valves, piping, and sensors as well as the corresponding module electronics control and the ancillaries into a single container making the best use of the limited space on board. The ancillaries comprise the equipment for supplying H2, O2, and N2 for reactant humidification, for product water, and waste heat and residual gas removal. The container is filled with N2 inert gas at 3.0 bar abs. to prevent a release of H2 and/or O2 in case of leakages. Thus, the operator can use the PEM Fuel Cell as a working black box without having to care about the processes inside the container. The PEM Fuel Cell module can be operated at various static and dynamic load currents. Currents below 650 A for FCM 34 modules or below 560 A for FCM 120 modules can be applied in continuous operation. The output power/current characteristics for FCM 34 modules are shown in Figure 8. For currents above the rated current, the loading time is limited due to insufficient heat removal at these values. Even loads up to double the rated current can be applied for a short time. At the rated operating point, the overall efficiency is approximately 59 percent with respect to the lower heat value of H2 (LHV). It increases in the part-load range, 8 reaching a maximum of approximately 69 percent at a load factor of some 20 percent of the rated current (approximately 100 A) (Fig. 9). The properties of the FCM 34 and FCM 120 modules are listed in the table on page 10. PEM Fuel Cell power plant Appropriate operating conditions for fuel-cell modules are provided for submarine applications by a fuel-cell system in which fuel cell modules are connected ◾◾ to the hydrogen and oxygen supply ◾◾ to disposal units for functions like – cooling – residual gas – reaction water ◾◾ to auxiliary systems for functions like – inert gas drying – degasing for cooling fluid – nitrogen supply – evacuation system ◾◾ to the propulsion/ship’s system as to supply it with demanded electrical power Efficiency [%/h0] Module output [kW] 180 160 140 120 70 60 50 100 40 80 30 60 FCM NG 160 kW FCM NG 135 kW FCM NG 80 kW FCM 34 FCM 120 40 20 0 80 0 350 700 1050 1400 Current [A] Fig. 8: Performance Data of FCMs – outlook on different CM NG configurations Operator control and visualization of the fuel-cell system are facilitated by the integrated platform management system or directly via the control panel of the fuel-cell system. Figure 10 gives a simplified overview of the AIP system. The fuel-cell system in its entirety – the complete fuelcell power plant, especially the supply and disposal ­systems described above for AIP operation, including spatial and functional integration on board – has been developed by HDW (Howaldtswerke Deutsche Werft AG). The submarine classes U 212 A, 214, and Dolphin are equipped with the new fuel-cell power plant by HDW based on SINAVY PEM Fuel Cell modules by Siemens. An AIP system with SINAVY PEM Fuel Cell modules can be added to existing submarines. 20 FCM NG FCM 34 FCM 120 10 0 0 200 400 600 800 1000 1200 Current [A] Fig. 9: Efficiency of FCM 34, 120, and NG a FCPP Switchboard 1 boats mains (main switchboard) FCM 34 or FCM NG b Converter FCM 120 FCPP Switchboard 2 FCPP peripheral ­devices: ◾◾ oxygen ◾◾ hydrogen ◾◾ product water ◾◾ residual gases ◾◾ cooling system ◾◾ evacuation ◾◾ ... EMCS EMCS boats mains (main switchboard) FCPP Switchboard c Fig. 10: Two types of fuel-cell power plants (FCPP) a: f uel-cell battery with FCM 34; direct coupling of ­ FC voltage to boats mains at class U 212 A submarine b: f uel-cell battery with FCM 120; coupling via converter at class U 214 submarine c: f uel-cell battery with n FCM NG, eg. n x 80 kW allows higher system availability Converter boats mains (main switchboard) FCM NG FCPP peripheral ­devices: ◾◾ oxygen ◾◾ hydrogen ◾◾ product water ◾◾ residual gases ◾◾ cooling system ◾◾ evacuation ◾◾ ... EMCS FCPP Switchboard 9 Number of Submarines 35 30 25 20 15 10 5 0 Siemens FCM Stirling Mesma other FCM Type of AIP System Fig. 11: Comparison of installed/contracted AIP Systems Fig. 12: PEM Fuel Cell modules assembled in a test rack Technical data FCM 34 FCM 120 FCM NG 80 FCM NG 135 Rated power 34 kW 120 kW 80 kW 135 kW* Voltage range 50–55 V 208–243 V 65–80 V 110–130 V Efficiency at rated load, approx. 59 % 54 % 54 % 54 % Efficiency at 20 % load, approx. 69 % 68 % 68 % 68 % Operating temperature 75 °C 75 °C 75 °C 75 °C H2 pressure 2.3 bar abs. 2.3 bar abs. 2.3 bar abs. 2.3 bar abs. O2 pressure 2.6 bar abs. 2.6 bar abs. 2.6 bar abs. 2.6 bar abs. H = 48 cm H = 50 cm W = 48 cm W = 53 cm L = 145 cm L = 176 cm 650 kg 900 kg Dimensions Weight (without module electronics) Similar to FCM 120 Similar to FCM 120 * The nominal load will be defined at the end of the development in range of 130–140 kW 10 Summary and Outlook SINAVY PEM Fuel Cell modules BZM 34 and BZM 120 are well-established in the market. They have proven their ­performance and reliability in extensive tests, including long-term tests on board of the Federal German Navy’s ­submarines, and have formed an integral part of an FC-based AIP systems for modern submarines like those of class U 212 A, 214, and Dolphin AIP for more than a decade. There is also the possibility to repower and refit operational submarines with an AIP system with SINAVY PEM Fuel Cell modules. The SINAVY PEM Fuel Cell technology’s field of application will be extended, when suitable reformers are available to produce hydrogen from liquid fuels, for example, methanol and diesel. Then, fuel cells may become the sole power source for the submarines of the future. With the ongoing R&D work on the 3rd generation (or BZM NG) fuel cells, an improved and more flexible ­module design will be prepared to fulfill future customer's expectations. 11 More information: www.siemens.com/marine Photo source: HDW, Blohm & Voss Siemens AG Industry Sector Marine & Shipbuilding P.O. Box 105609 20099 HAMBURG GERMANY E-mail: marine@siemens.com Subject to change without prior notice 06/13 Order No.: E20001-A460-T197-X-7600 Dispo 16600 TH 464-130518 | WS | 06131. GD.LD.VM.XXMS.52.3.03 Printed in Germany © Siemens AG 2013 The information provided in this brochure contains merely general descriptions or characteristics of performance which in case of actual use do not always apply as described or which may change as a result of further development of the products. An obligation to provide the respective characteristics shall only exist if expressly agreed in the terms of contract. 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