A keel cooler assembly comprising a liquid coolant tube including a plurality of turbulence enhancers for improving the heat transfer of the liquid coolant without substantially increasing pressure drop of the liquid coolant. In one embodiment, the turbulence enhancers generate turbulent wakes in the liquid coolant for disrupting laminar boundary layers for improving heat transfer. In another embodiment, the turbulence enhancers generate and propagate turbulent vortexes in the liquid coolant to enhance mixing of the bulk liquid coolant for improving heat transfer. In other embodiments, turbulators, including inserts or impediments, are provided having various configurations and being arranged in predetermined patterns for enhancing turbulence of the liquid coolant for improving keel cooler heat transfer efficiency without substantially increasing pressure drop.

A sea water cooling system including a first fluid cooling loop coupled to a first side of a heat exchanger and to a thermal load, a second fluid cooling loop coupled to a second side of the heat exchanger and including a pump for circulating fluid through the second fluid cooling loop, and a controller operatively connected to the pump, wherein the controller is configured to monitor an actual temperature in the first fluid cooling loop and to adjust a speed of the pump based on the monitored temperature to achieve a predetermined temperature in the first fluid cooling loop. The system may be selectively operable in one of a plurality of operating modes accordance, wherein in a first operating mode the pump is operated based entirely on cooling demands of the thermal load, and in a second operating mode the pump is operated to maintain a fluid pressure above a predefined pressure.

The present application provides a cooling shell, a chassis, a marine electric propulsor, and a cooling control method. The cooling shell includes a shell body and the shell body includes a fin portion, a heating component installation portion, and a cooling component installation groove. The heating component installation portion is formed on one side of the shell body in the first direction for installing the heating component. The cooling component installation groove is formed on the other side of the shell body for accommodating the cooling component. A connected flow channel is formed between the fin portion and the cooling component installation groove.

A marine drive is configured for propelling a marine vessel in a body of water. The marine drive has a transom bracket assembly configured to mount the marine drive to the marine vessel, a drive assembly coupled to the transom bracket assembly and configured to generate a thrust force in the body of water, the drive assembly being trimmable up and down relative to the transom bracket assembly, a cooling water pump configured to pump cooling water from the body of the water for cooling at least one component of the marine drive, and a rigid cooling water conduit extending from the drive assembly to the transom bracket assembly, the rigid cooling water conduit being configured to convey the cooling water from the drive assembly to the cooling water pump.

A pod propulsion device includes: a pod configured to be disposed in water; a rotation shaft supported by the pod to be rotatable about a predetermined axis and having an end portion projecting out from the pod; a screw fixed to the end portion of the rotation shaft; an electric motor installed in the pod to rotationally drive the rotation shaft; multiple guide blades integrally formed on the pod to be arranged at intervals in a circumferential direction of the pod, each guide blade extending out radially from an outer surface of the pod; and a cooling circuit for cooling the electric motor, wherein the cooling circuit includes a cooling liquid passage formed to pass through an interior of at least one of the guide blades.

A heat exchange system for use on an engine-powered watercraft includes a liquid cooling system for cooling the engine using a first heat exchanger and a water heating system using a second heat exchanger for heating water. Raw water from an external water source is passed through each heat exchanger. Water used to cool the engine coolant inside the first heat exchanger exits the watercraft. Water heated by the second heat exchanger is passed to either an intake conduit or at least one onboard accessory system for flushing thereof to kill aquatic invasive species. A valve inside the second heat exchanger opens to release heated water when the heated water reaches a temperature of at least 140 F. Heated coolant from the first heat exchanger passes through the second heat exchanger to transfer heat to the water inside the second heat exchanger.

A cooler for cooling a marine transmission gearbox by a cooling fluid. The cooler (1) comprises a cooler housing (2) which is made of plastic and a heat sink element (3) which is arranged at least partially inside a cavity (39) of the cooler housing (2) so that the heat sink element (3) is in contact with the cooling fluid, during operation. The heat sink element (3) is attachable to the gearbox housing (4) of the marine transmission gearbox in such a way that heat is transferable from the gearbox housing (4), via the heat sink element (3), to the cooling fluid. A marine transmission gearbox with such a cooler (1) is also part of the present invention.

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.

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.

A marine engine quick drain system is provided having multiple drainage tubes connecting each drainage point on the marine engine to a water removal device. The water removal device is operable to drain water from all drain ports within the engine simultaneously, routing all drain ports to single point drain which is preferably connected to vacuum for evacuating fluids from the marine engine. Fittings are provided to connect each drainage tube to each drainage point on the marine engine. Integrated within each fitting is a fluid sensor which indicates the presence of water in each part of the engine. Each sensor is connected back to a central control console having a microprocessor which will control the water removal device and verify that the marine engine has been drained properly or if there is water in the marine engine.