The present invention includes an underwater vehicle power unit and method of operating the same comprising: a fuel and waste stack comprising one or more reactant or fuel storage bladders and one or more waste storage bladders; a heater; a reactor that generates hydrogen and waste; a hydrogen and waste separator; a back-pressure regulator; a hydrogen and liquid separator; a fuel cell; and a controller that controls the temperature of the heater, the flow of fuel into the reactor, the flow of hydrogen into the fuel cell, the flow of water that dilutes the fuel, the flow of waste from the reactor and/or the fuel cell into the one or more waste storage bladders.

According to some embodiments, a flexible regasification system comprises a floating liquefied natural gas (LNG) storage vessel; a LNG vaporizer disposed on a jetty proximate the LNG storage vessel to vaporize the LNG into natural gas; and a thermal fluid source. The LNG storage vessel is coupled to the LNG vaporizer and supplies LNG to the LNG vaporizer. The thermal fluid source is coupled to the LNG vaporizer and sends heated thermal fluid to the LNG vaporizer for converting the LNG to natural gas, which converts the heated thermal fluid to a cooled thermal fluid. The cooled thermal fluid is discharged back to the thermal fluid source, comprising a closed loop. In particular embodiments, the thermal fluid storage comprises a floating vessel disposed near the jetty. In some embodiments, the cooled thermal fluid from the LNG vaporizer is first sent to a power plant or refrigeration plant.

An engine includes an engine stop switch for stopping the engine, and a cooling part included in a holding portion or passage of a cooling liquid. The engine stop switch is placed at the cooling part or at a peripheral part of the cooling part.

A heat exchanger for a marine engine has a housing with an internal cavity. Twisted tubes snake back and forth inside the cavity and carry a first fluid to cool a second engine cooling fluid flowing through the cavity. Each of the twisted tubes has a plurality of ridges to increase the surface area of the tube exposed to the second fluid. Dividers inside the cavity direct the flow of the second fluid through the cavity. The housing may have a removable cover to access the housing cavity.

An exhaust system for a marine exhaust system includes two riser conduits, each being connected to a Y-pipe at an outlet end. An inner tube of each riser conduit directs exhaust gases through a catalytic converter assembly and into the Y-pipe. An outer tube surrounds each inner tube to define a cooling liquid passage between the inner and outer tubes to direct cooling liquid into one of the inlets of the Y-pipe. A bellows couples one of the riser conduits to one of the inlets of the Y-pipe. Each bellows surrounds one of the inlets of the Y-pipe and one of the riser conduits. To minimize reversion, the inner tube of each of the riser conduits extends into one of the bellows further than the outer tube of the respective riser conduit.

A cooling apparatus (1) for cooling a fluid by means of surface water comprises a plurality of tubes (10) for containing and transporting the fluid to be cooled in their interior, the tubes (10) being intended to be at least partially exposed to the surface water during operation of the cooling apparatus (1). Furthermore, the cooling apparatus (1) comprises a plurality of light sources (21, 22) for producing light that hinders fouling of the exterior of the tubes (10), the light sources (21, 22) being dimensioned and positioned with respect to the tubes (10) so as to cast anti-fouling light over the exterior of the tubes (10), wherein the light sources (21, 22) have a generally elongated shape, and wherein the light sources (21, 22) are arranged in at least two mutually different orientations in the cooling apparatus (1).

A seawater cooling system adapted to mitigate salt crystallization in a seawater cooling loop. The system may include a pump operatively connected to the cooling loop and configured to pump seawater through the cooling loop, a temperature sensor operatively connected to the cooling loop and configured to monitor a temperature of the seawater in the cooling loop, and a controller operatively connected to the temperature sensor and to the pump, the controller configured to issue a warning and to increase a speed of the pump if it is determined that the monitored temperature of the seawater exceeds a predetermined threshold temperature.

The embodiment of the invention provides a marine diesel power system comprising a diesel engine, a conformal heat exchanger with a first inlet and a first outlet thereof connected to the diesel engine and upper and lower sealing heads thereof as well as a second inlet and a second outlet for inflowing and discharging seawater, and a jet device at a second outlet of the conformal heat exchanger, wherein a first inlet, a second inlet and an outlet of the jet device are separately used for sucking seawater discharged from the second outlet, connecting to a diesel engine exhaust tube and discharging seawater and waste gas discharged from the diesel engine exhaust tube. By arranging the jet device at the second outlet, the heat exchange form of the conformal heat exchanger is changed into forced convection heat exchange, so that the heat exchange efficiency of the conformal heat exchanger is improved.

A closed-loop cooling ship propulsion apparatus includes a power device, a pump, and a coolant supply. A fluid circuit is formed in the ship propulsion apparatus and a coolant in the loop can be arranged to circulate through all heat-generating components in addition to the pump and motive power unit. A closed-loop circuit avoids the blockages and contamination which might occur if the water of a sea or lake was used directly.

An exhaust system for a marine exhaust system includes two riser conduits, each being connected to a Y-pipe at an outlet end. An inner tube of each riser conduit directs exhaust gases through a catalytic converter assembly and into the Y-pipe. An outer tube surrounds each inner tube to define a cooling liquid passage between the inner and outer tubes to direct cooling liquid into one of the inlets of the Y-pipe. A bellows couples one of the riser conduits to one of the inlets of the Y-pipe. Each bellows surrounds one of the inlets of the Y-pipe and one of the riser conduits. To minimize reversion, the inner tube of each of the riser conduits extends into one of the bellows further than the outer tube of the respective riser conduit.