Diesel generator set radiator internal structure commonly used has two kinds of tube-fin type and tube-band type. The internal structure of the fin type, it is composed of many flat water pipes welded on the multi-layer heat sink. Its core has a large heat dissipation area, small resistance to airflow, good structural rigidity, strong pressure-bearing capacity, and is not easy to break, so it is currently widely used. The disadvantage is that the manufacturing process is more complicated.
The inside of the tube belt is composed of a corrugated heat dissipation belt 8 and a flat tube 9 alternately arranged and combined. There are slots 10 on the belt, which can break the air flow attached surface layer to increase the heat transfer effect. The rigidity of the core part is not as good as the tube sheet type, but the manufacturing process is simple, which is convenient for mass production, and its applications are gradually increasing.
The radiator core of the diesel generator set is mostly made of brass. Brass has good thermal conductivity and corrosion resistance, is easy to form, has sufficient strength and is easy to weld and repair. In order to save copper, in recent years, Shanghai generator aluminum alloy radiator has also developed to a certain extent.
Closed forced circulation cooling system is a closed system. After increasing the vapor pressure of the system, the boiling point of the cooling water can be increased. As the temperature difference between the cooling water temperature and the outside air temperature increases, the heat dissipation capacity of the entire cooling system is improved. However, if the steam pressure in the cooling system is too high, it may rupture the welds or water pipes of the radiator core.
When the water vapor in the cooling system condenses, the vapor pressure in the system will be lower than the outside atmospheric pressure. If this pressure is too low, the radiator core may be damaged by the outside atmospheric pressure. Therefore, the water tank cover of the closed cooling system is equipped with an air-steam valve, otherwise it will affect the price of the generator.
When the steam pressure in the cooling system is lower than the atmospheric pressure by 0.01 to 0.02 MPa, under the action of the pressure difference, the air valve 3 overcomes the preload of the spring and opens. The air enters the upper water tank through the air valve from the steam outlet pipe 5, which increases the pressure of the cooling system.
When the steam pressure in the cooling system exceeds the atmospheric pressure by 0.02～0.03MPa, the steam valve spring 2 is compressed, and the steam valve 1 opens. At this time, a part of steam will be released from the steam extraction pipe 5 to reduce the pressure of the cooling system. At this time, the boiling point of the cooling water can be increased to about 108°C, reducing the consumption of cooling water.
Post time: Aug-26-2021