USA As Represented by Secretary of the Navy

Donald T Knauss

Herman B Urbach

Anthony J Digiovanni

Denis J Colahan

The present invention describes methods and apparatus for controlling the humidity of air supplied to cooling coils on a gas turbine powered ship through a dynamic desiccation system. The system passes supply air through a desiccant wheel, which dries and concomitantly heats the supply air. This supply air stream is then passed through a rotatable thermal wheel, wherein heat is transferred from the dry supply air to an exhaust-air mixture, thereby conditioning the supply air for delivery and circulation to a plurality of cooling-coil units in a plurality of compartments. The exhaust air from the compartments is first mixed with some of the treated supply air to lower the absolute humidity to a value needed for effective regeneration of the desiccant wheel. An evaporative cooler then conditions the exhaust-air mixture for effective cooling of the supply air in the thermal rotor, which also serves as an air preheater for desiccant regeneration. The exhaust-air mixture is then heated to the desiccant regeneration temperature by passing the preheated exhaust air through a heat exchanger supplied with gas-turbine waste heat. After this heated exhaust-air mixture regenerates the desiccant wheel by fully drying out the desiccant on the wheel, it is expelled from the fan room.

Dynamic desiccation cooling system for ships

A forced-recirculation boiler (FRB) type of heat-recovery steam generator is applied to a ship-propulsion application of the recuperative dual-fluid engine. Such boilers generally include an economizer, evaporator and superheater, and incorporate a steam drum for controlling the flow of water-steam mixture through the evaporator. By altering the flow system of the FRB, the stability and integrity of the boiler are maintained by simultaneously providing, under any predetermined off-design, gas-side flow conditions, means for (1) limiting the gas-side cold corrosion of said boiler tubes through tube-wall temperature control, and (2) introducing a controllable sensible component into the heat load of said evaporator, thereby enabling, for any predetermined off-design steam rate, stable evaporator operation at a predetermined design steam quality. One embodiment of the invention is achieved by adding to the flow circuit of the economizer a recirculation loop that enables, through diversion of the water flows within the loop, the conditioning of the flows to both the economizer and the steam drum. Simulation of the operation of the flow-system invention along the power-profile curve of the engine has demonstrated the efficacy of the flow-system in enabling, at any particular point on the power-profile curve, the predetermined steam rate needed for optimum performance of the engine.

Flow control system for a forced recirculation boiler

A steam-augmented gas turbine engine system generally includes a compressor 3), first and second combustors (4a, 4b), a compressor turbine (6) and a power turbine (7). A heat exchanging system (8b) removes heat from an exhaust product from the power turbine (7) and preheats water which has been desalinated by a water purification system (12). The desalinated water is provided to the first combustor (4a), as a predetermined quantity of water-steam mass, along with fuel and compressed air, and is used to efficiently power the turbine system. In one embodiment, a two-boiler system (8b) is employed in which first and second steam outputs are provided to first and second combustors (4a, 4b) such that a mass flow of the compressor turbine (6) is substantially constant from a Cheng point to a stoichiometric point of a predetermined power profile. This constancy of mass flow ensures that the gas generator operates on design from the Cheng point to the stoichiometric combustion point. Additionally, the free-power-turbine (7) always operates on design.

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Severna Park, MD, United States of America

Donald T Knauss