Marine heat exchangers the most common way to cool a boat’s engine, using the lake, river or ocean water in which the boat floats. Since this water may be corrosive the engine may be cooled by a sealed mixture of distilled water and antifreeze. Marine heat exchangers from the water-antifreeze mixture is then transferred to the ocean (or lake or river) water which flows into a heat exchanger. The water-antifreeze mixture runs through the Marine heat exchangers dumping heat, but remaining separate from corrosive salts and chemicals found in the water the boat is floating in. If the ocean water eventually corrodes and ruins the heat exchanger it can be replaced at a fraction of the cost of replacing the engine. To protect the marine heat exchanger from corrosive salts, a sacrificial zinc anode is screwed into the Marine heat exchangers. This anode must be periodically replaced as part of regular maintenance. Because the water the boat floats in may be contaminated with floating particles such as wood or styrofoam balls the well designed boat will have a filter (often stainless steel mesh) to remove these particles before they are moved toward the heat exchanger. This filter must be periodically cleaned or else the flow of water to the heat exchanger will become obstructed and the engine will overheat.
Large ships usually carry evaporating plants to produce fresh water, that reducing their reliance on shore-based supplies. Steam ships must be able to produce high quality distillate in order to maintains boiler-water levels. Diesel engined ships often utilise waste heat as an energy source for producing fresh water. In this system, the engine cooling water is passed through a heat exchanger, where it is cooled by concentrated sea water (brine). Because the cooling water (which is chemically treated fresh water) is at a temperature of 70-80 degrees C, it would not be possible to flash off any water vapour unless the pressure in the heat exhanger vessel was dropped. To alleviate this problem, a brine-air ejector venturi is used to create a vacuum inside the vessel. Partial evaporation is achieved and the vapour passes through a demister before reaching the condenser section. Sea water is pumped through the condenser section to cool the vapour sufficiently to precipitate it. Sea water temperature can interfere with productions, as can fluctuations in engine load. For this reason, the evaporators is adjusted as sea water temperature changes, and shut down altogether when the ship is manoeuvring. An alternative in some vessels, such as naval ships and passenger ships, is the use of the Reverse Osmosis principle for fresh water production instead of evaporators.The distillate gathers in a tray, from where it is pumped to the storage tanks. A Salinometer monitors salt content and diverts the flow of distillate from the storage tanks if the salt content exceeds the alarm limit. Sterilisation is carried out after the evaporators. Evaporators are usually of the shell-and-tube type (known as an Atlas Plant) or of the Plate Type (such as the type designed by Alfa Laval). Temperature, production and vacuum are controlled by regulating the system valves.
Marine Heat Exchanger Advantages
- The exchangers are very high efficient and best product.
- High Quality design with high heat transfer ability.
- The advantages and problem areas with different heat exchanger types and materials are discussed.
- Marine heat exchanger is its size, cost and ease of adapting existing cold water systems to hot.
- Researchers, over the years, have used a variety of heat exchanger types and materials.
- The application of heat exchangers to large scale marine aquaculture.
Marine Heat Exchanger Applications
- Marine heat exchangers are the most common way to cool a boat’s engine, and
- Gear Oil Coolers
- Fuel Coolers
- Hydraulic Oil Coolers
- Diesel Fuel Return Coolers
- Combination Coolers in Tandem
- Lube Oil Coolers