Abstract: A pontoon that includes infrastructure for fluidically coupling a heat exchanger or heat exchanger module into each of the seawater and working-fluid distribution systems of an OTEC power generation system is provided. In some embodiments, a pontoon comprises: (1) a first passage for conveying seawater between a first port and a second port at which a heat exchanger module can be connected; and (2) a conduit and connectors for connecting the heat exchanger module and the working fluid circulation system—even while the heat exchanger module is submerged. In some embodiments, pontoons in accordance with the present invention enable heat exchangers or heat exchanger modules to be added or removed to an OTEC system without disrupting the operation of other heat exchangers or heat exchanger modules in use in the OTEC system.

Abstract: Various embodiments of the invention relate to enclosure assemblies housing at least one electronic board assembly and systems (e.g., missiles or unmanned vehicles) that may employ such enclosure assemblies. In an embodiment, an enclosure assembly includes an enclosure having an interior surface defining an interior space and an inner diameter. At least one electronic board assembly is positioned within the interior space and includes a first peripheral edge region and an opposing second peripheral edge region. The electronic board assembly extends diametrically so that the first and second peripheral edge regions are at least proximate to the interior surface. In another embodiment, a plurality of electronic board assemblies are positioned within the interior space and each extends generally along a respective non-diametric chord defined by the interior surface.

Abstract: A method for extracting fuel gases from an underwater plume emitted from an underwater hydrothermal vent includes the step of collecting via an underwater fluid collector an underwater plume emitted from the hydrothermal vent. The underwater plume includes methane and hydrogen. The method further includes a step of directing a first fluid containing the underwater plume into a first inlet of a first underwater heat exchanger and a second fluid into a second inlet of the first underwater heat exchanger. The second fluid at the second inlet is at a temperature sufficiently lower than the temperature of the first fluid to transfer sufficient heat therebetween to form methane hydrate and hydrogen-methane hydrate in the first fluid. The method further includes the step of conveying the methane hydrate and hydrogen-methane hydrate to the surface of the water body via a duct connected to a first outlet of the first heat exchanger.

Abstract: A power system based on a binary power cycle and utilizing a multi-component working fluid is disclosed. The working fluid is partially vaporized and a split recirculation approach is used to control the enthalpy-temperature profiles to match the heat source. A portion of the unvaporized working fluid is sprayed into the condenser.

Abstract: A heat exchanger and a method for fabricating the heat exchanger are disclosed. The heat exchanger comprises a heat exchanger core that is formed from a plurality of stacked aluminum panels that are joined together via friction stir welding. Each panel in the core is formed from at least two aluminum extrusions that are joined to one another via friction stir welding.

Abstract: A modular heat exchanger that can be submerged to great depths and then easily recovered in order to reduce the costs and disadvantages of the prior art. Because the heat exchanger is submergible and recoverable, it can be more easily maintained. This ease of maintenance allows the heat exchangers to be deployed at greater depths. This, in turn, allows for greater differences in temperatures, greater efficiency for the heat engine, and a more effective ocean thermal energy conversion system.

Abstract: A power generation system that comprises a first power generator; a first turbine operable to drive the first power generator; a vaporizer operable to vaporize a working fluid, wherein the vaporized working fluid turns the first turbine; and a condenser operable to condense the vaporized working fluid exiting the first turbine, wherein the condenser is coupled to the vaporizer such that the condensed working fluid is vaporized in the vaporizer. The power generation system also comprises a second power generator; a second turbine operable to burn a fuel to drive the second power generator; a switch to selectively operate the second turbine independently of the first turbine; and a heat exchanger coupled to the second turbine to receive flue gas from the second turbine when operated, wherein heat is transferred in the heat exchanger from the flue gas to the vaporized working fluid after the vaporized working fluid exits the vaporizer and prior to the vaporized working fluid entering the first turbine.

Abstract: Shell-and-tube heat exchangers that utilize one or more foam heat transfer units engaged with the tubes to enhance the heat transfer between first and second fluids. The foam of the heat transfer units can be any thermally conductive foam material that enhances heat transfer, for example graphite foam. These shell-and-tube heat exchangers are highly efficient, inexpensive to build, and corrosion resistant. The described heat exchangers can be used in a variety of applications, including but not limited to, low thermal driving force applications, power generation applications, and non-power generation applications such as refrigeration and cryogenics. The foam heat transfer units can be made from any thermally conductive foam material including, but not limited to, graphite foam or metal foam. In an embodiment, the heat exchanger utilizes tubes that are twisted around a central foam heat transfer unit.

Abstract: Heat exchangers are described that employ fins made of a heat conducting foam material to enhance heat transfer. The foam fins can be used in any type of heat exchanger including, but not limited to, a plate-fin heat exchanger, a plate-frame heat exchanger or a shell-and-tube heat exchanger. The heat exchangers employing foam fins described herein are highly efficient, inexpensive to build, and corrosion resistant. The described heat exchangers can be used in a variety of applications, including but not limited to, low thermal driving force applications, power generation applications, and non-power generation applications such as refrigeration and cryogenics. The fins can be made from any thermally conductive foam material including, but not limited to, graphite foam or metal foam.

Abstract: A spar platform comprises one or more continuous-fiber composite tubes fabricated at or near the intended site use of the platform. In some embodiments, the spar platform includes a relatively longer central tube and relatively shorter peripheral tubes. In some other embodiments, the spar platform is a single long tube. In some embodiments, the spar platform supports a wind turbine assembly. The continuous-fiber composite tubes are formed, in either a vertical or horizontal orientation, using a modified vacuum assisted resin transfer molding process.

Abstract: Various embodiments of the invention relate to electronics modules, enclosure assemblies housing at least one such electronics module, and systems (e.g., missiles or unmanned vehicles) that may employ such enclosure assemblies. In one embodiment, an electronics module includes a first plate extending generally in a first plane, and a second plate spaced from the first plate and extending generally in a second plane. The electronics module further includes a plurality of electronic board assemblies each of which extends generally in a respective plane and is in thermal communication with at least one of the first and second plates. Each electronic board assembly may be positioned between the first and second plates and oriented so that the respective plane thereof is non-parallel relative to the first and second planes.

Abstract: A heat exchanger module for thermally coupling a first fluid and second fluid is disclosed. The heat exchanger module comprises a plurality of heat exchangers, each of which is fluidically coupled to a common seawater inlet and a common seawater outlet. The heat exchanger module is dimensioned and arranged for integrating with an OTEC system located on an offshore platform that is deployed in a body of water. The heat exchanger module physically and fluidically couples with ports included in pontoons attached to the offshore platform. The ports are individually controllable so that the module can be added or removed from the OTEC system without interrupting operation of other heat exchanger modules integrated with the OTEC system.

Abstract: A heat-exchanger module that conveys a fluid through one or more heat exchangers with little or no pressure drop is presented. The heat-exchanger module comprises a first manifold that smoothly channels the fluid from a fluid source to each of the heat exchangers. The heat-exchanger module further comprises a second manifold that smoothly channels the fluid from the heat exchangers to a fluid sink. The manifolds are dimensioned and arranged to mitigate development of pressure drops in the fluid flow.

Abstract: A pontoon that includes infrastructure for fluidically coupling a heat exchanger or heat exchanger module into each of the seawater and working-fluid distribution systems of an OTEC power generation system is provided. In some embodiments, a pontoon comprises: (1) a first passage for conveying seawater between a first port and a second port at which a heat exchanger module can be connected; and (2) a conduit and connectors for connecting the heat exchanger module and the working fluid circulation system—even while the heat exchanger module is submerged. In some embodiments, pontoons in accordance with the present invention enable heat exchangers or heat exchanger modules to be added or removed to an OTEC system without disrupting the operation of other heat exchangers or heat exchanger modules in use in the OTEC system.

Abstract: An Ocean Thermal Energy Conversion (OTEC) system comprising a self-contained submersible OTEC plant is disclosed. The OTEC plant comprises a electrical generation system and a thermal mass whose temperature is based on the temperature of water at a first depth of a body of water. The OTEC plant is moved to a second depth of the body of water, wherein water at the second depth is a different temperature that the water at the first depth. The OTEC system generates electrical energy based on a difference in the temperatures of the water at the second depth and the temperature of the thermal mass. The OTEC system is able to generate electrical energy at either of the first depth and the second depth.

Abstract: An Ocean Thermal Energy Conversion (OTEC) system is disclosed. The OTEC system generates electrical energy based on a difference in the temperatures of the water from a surface region of a body of water and a thermal mass whose temperature is based on the temperature of water from a deep water region of the body of water. The thermal mass attains a desired temperature while it is positioned in the deep water region, with which it is thermally coupled. The present invention uses a bulk transport vessel to carry the thermal mass from the deep water region to a depth where it can be thermally coupled with the OTEC system.

Abstract: A heat exchanger comprising a plurality of plates that are demountably attached to a frame is disclosed. Each plate comprises a plurality of channels for conveying a primary fluid through the heat exchanger. The frames are arranged in the frame so that spaces between adjacent frame pairs define conduits for conveying a secondary fluid through the heat exchanger. The plates are mounted in the frame so that they can be individually removed from the frame. Further, each of the channels is fluidically connected to input and output ports for the primary fluid by detachable couplings. As a result, heat exchangers in accordance with the present invention are more easily repaired or refurbished than prior-art heat exchangers.

Abstract: A heat exchanger comprising helically wound tube bundles is disclosed. The helically wound tube bundles are joined with tube sheets to define a primary working fluid system that is fluidically isolated from a secondary working fluid system. The tube sheets and tubes are formed of the same material, which facilitates their joining by means of joints that are substantially galvanic corrosion-resistant joints.

Abstract: A hybrid plate-fin heat exchanger for exchanging heat between a first fluid and a second fluid is disclosed. The hybrid plate-fin heat exchanger comprises a plurality of plates, each of which comprises channels for conveying the first fluid. Fins are brazed onto each plate, wherein the fins define a plurality of flow channels for the second fluid. The plates are joined to one another via friction-stir welding in such a way that the brazed regions are fluidically isolated from the first fluid during operation. As a result, the heat exchanger is suitable for use in applications that use a first fluid, such as seawater or geothermal fluid, which is corrosive for the brazed regions.

Abstract: A power system based on a binary power cycle and utilizing a multi-component working fluid is disclosed. The working fluid is partially vaporized and a split recirculation approach is used to control the enthalpy-temperature profiles to match the heat source. A portion of the unvaporized working fluid is sprayed into the condenser.