Introduction of Plate Heat Exchanger in Marine Turbine
In marine turbine, the heat exchange is undoubtedly a very critical factor to ensure the normal use of the engine. Because when the turbine is working, it needs to maintain a certain temperature to ensure the normal operation of the machine. There are many kinds of heat exchangers used in marine engine, in which plate heat exchanger is one of the very important one, and will be the very popular potential equipment on vessels in the future.
The heat exchanger has been one of the indispensable equipments in marine engine, which can be applied in the main and auxiliary oil cooler, cylinder liner fresh water cooler, fuel heater, steam condensers, water heater and other equipments. The special working environment of the ship has very special demanding on the heat exchanger, including the factors such as instability in the sea, which may encounter vibration, shock, large angle tilt and noise. The cooling medium is usually seawater, which is with high salt concentration, high humidity of the working environment, and very strong corrosion of the plate. The marine itself is very compact in structure, having more stringent restrictions on the heat exchanger space and quality. The heat transfer medium of traditional heat exchanger is always water, and the heat transfer medium of marine heat exchangers is generally oil and water and so on. The emergence of plate heat exchanger effectively solves a large part of the problem.
The Role of Cooling Water System
Some of the mechanical equipment in the diesel engine power produces heat in the normal operation. The heat must be distributed in time; otherwise the heating element temperature will continue to rise, more than allowable limits and will damage the reliability of mechanical equipment. In order to distribute these calories immediately in efficient manner, in common let a certain amount of liquid to flow continuously through the heat sink and bring the heat out of the equipment. Cooling systems typically use fresh water, seawater or river water as a cooling medium.
A lot of heat took away by cooling system is residual heat burn done by fuel, generally about 20% to 30%. As the diesel engine is one of a heat engine, is to rely on the combustion of fuel heat to work, so it is loose to take away the heat. Obviously, the more the intense of cooling, the greater the loss of this part is, and the more obviously the reduction of diesel economy. On the other hand, since the temperature of the heat-receiving member is high, the average temperature in the inner wall of the cylinder can reach 200 ° C to 300 ° C, and the surface temperature in contact with the cooling water is low, the thermal stress is liable to occur at such a temperature difference. The temperature difference is too large to crack the part.
It can be seen, the diesel engine has strict requirements on cooling process. The effect of the cooling system is to cool the diesel engine forced, the temperature of each heated part is controlled within the allowable range and at the same time maintain the proper cooling water temperature and use the proper cooling medium to ensure its normal and reliable operation.