The works presented in the current section contain patentable technical solutions that allow obtaining considerable effectiveness of studied equipment and processes.
Non-AIP conventional diesel-electric attack submarine Type-209 has been investigated. As it follows from HYPERLINK HYPERLINK the Type-209 is a class of diesel-electric attack submarine developed exclusively for export by Howaldtswerke-Deutsche Werft (HDW) of Germany. Five variants of the Type 209/1100-1500 have been successfully exported to 13 countries, 61 submarines being built and commissioned between 1971 and 2008. One of the common drawbacks of this class submarines is absence of AIP system. Only one boat Type 209/1200 Poseidon class of the Greek Navy under the Neptune II upgrade program was equipped with AIP system. The 120 kW Siemens’s AIP system is located in separate 6.5 m section that was fitted into aft part of submarine Okeanos (S-118) that in 1979 was commissioned. We propose the new concept of CCD AIP system. Such system has simple and compact design. The system is intended to develop a brake power up to 300 or 600 kW. Existing non-AIP submarines can be fitted with new CCD AIP without cutting-in an additional AIP section in submarine’s hull.
Hydrogen production from ammonia has been studied. Ammonia’s temperature and pressure, catalysts and their supports define as hydrogen yield so reaction rate and consequently ammonia-cracker dimensions and its cost as well. Ruthenium is the best catalyst for ammonia decomposition at 400 °C. As for Nickel, it is the base catalyst for ammonia decomposition at 600 °C. Obviously, the lower reaction temperature the higher longitude and the higher cost of the device. Carbon nano-tubes are very effective as a support for Ruthenium-based catalysts. Although the decomposition rate is lower for Nickel than Ruthenium at a given temperature, the higher loading of Nickel is permissible because it has lower cost. Nickel also allows for the using of nano-sized particles, which have shown the decomposition rates comparable to Ruthenium catalyst. The development of catalysts and reaction promoters is important for cracker design optimization that in turn influence on performance of hydrogen generation. Catalyst and ammonia-gas preheating optimization is a feature influencing on longitude of a hydrogen generation system.
Proton Exchange Membrane fuel cells are adversely affected by ammonia because of reduced conductivity of Nafion and decreased activity of the catalyst layers. Alkaline fuel cells (AFC) are unaffected by ammonia but are unlikely to be commercially pursued because of the inherently poor performance associated with non-solid state technologies. Ammonia can be used as a fuel for Solid Oxide Fuel Cells (SOFC) and Protonic Ceramic Fuel Cell (PCFC). The SOFC provides high power densities (100 -1000 mW/cm² for both proton-conducting and oxygen ion-conducting electrolytes). Ammonia is fed into SOFC’s anode. Inside anode, at the high operating temperatures of SOFC ammonia is decomposed (NH3=>1.5H2+0.5N2) on Ni-based catalyst. Whereupon, in the SOFC chemical energy of hydrogen is converted into electricity due to a chemical reaction of positively charged hydrogen ions with oxygen. In fact, anode of SOFC acts the part of ammonia cracker. One of the challenges connected with using ammonia as the direct fuel for SOFC is nitrogen utilization at SOFC exhaust. We considered some ways of nitrogen utilization. Comparative analysis of nitrogen utilization had been completed.
The main goal of this publication is to show that dissolved oxygen (DO) extracted from seawater can be used as a real source of oxygen for submarine’s AIP systems. In particular, the feasibility analysis shows that suggested technical solutions enable to provide the submerged operation of 300kW fuel cell AIP system.
Obviously, that sea trial results only will be able to demonstrate feasibility of the technical proposal.
Atmospheric air contacting with seawater is solved in water partially. Essentially, it is concerned of all gases is being contained in air. Theoretically solubility of gases in water is based on Henry law. It is known that the main gases dissolved in seawater are: oxygen (O2), nitrogen (N2) and carbon dioxide (CO2). These gases have maximal partial pressures and relatively low values of Henry coefficient (KH). It provides relatively high solubility of the gases in seawater.
The oxygen solubility in seawater depends on water temperature, depth and salinity. The content of oxygen is considered against to Ocean’s latitudes, littoral waters and open sea, seasons, and time of day. In this connection, it is evaluated the minimal, average and maximal concentrations of oxygen in littoral waters at the typical depth of submarine patrol operations.
To provide the extracting oxygen from seawater with maximal efficiency the pervaporated membrane technology had been selected
The feasibility analysis includes some following steps:
This publication is intended for investors that are interested in submarine AIP systems development and, in particular, are ready to invest detailed design, manufacturing and sea trials of systems for dissolved oxygen (DO) extraction from seawater.