There are two cooling methods for diesel generator sets: air cooling and water cooling.
1. Air Cooling
The air cooling method uses air as a cooling fluid to transfer heat from the heated parts of the diesel engine. The method consists of a cooling fan and a guide cover.
In order to increase heat dissipation neps, many corrugated fins are usually cast on the outer walls of the cylinder block, cylinder head and each radiator. During operation, the fan rotates to circulate air along the air guide cover to the surface of the cylinder block and cylinder head. As cold air passes through the heat sink, it carries away heat from the cylinder block and cylinder head.
2. Water cooling
The cooling methodWater heating uses water as a cooling fluid to transfer heat from heated parts of the diesel engine. The characteristic of this cooling method is that it is easy to adjust the cooling intensity when the temperature or workload changes.
There are two types of water cooling methods: open type and closed type. In an open cooling system, the circulating water is directly connected to the atmosphere and the steam pressure in the cooling system is always maintained at atmospheric pressure. In a closed system, water circulates in the closed system and the vapor pressure of the cooling system is greater than atmospheric pressure. As the temperature difference between the cooling water temperature and the outside air temperature increases, the heat dissipation capacity of the assembly increases. the cooling systemst improved.
The cooling of synchronous generators is divided into two types: external cooling and internal cooling:
1. External cooling: including air cooling and hydrogen cooling
Air cooling: the cooling medium is air, that is, air is used to exhaust the heat generated due to losses in the generator. This method has a simple structure, but the cooling efficiency is not high. The maximum installed capacity can reach about 100 MW;
Hydrogen cooling: the cooling fluid is
hydrogen, i.e. hydrogen is used to dissipate heat. High cooling capacity compared to air. The ventilation loss is low, but the structure is complex and requires hydrogen storage equipment. The maximum installed capacity can reach around 200 MW;
2. Internal cooling: including stator internal water cooling, rotor internal hydrogen cooling, etc.
Internal cooling (direct cooling method): the cooling medium is l water, oil, hydrogen, that is to say, hydrogen, water or oil passes through the inside of the wire to directly dissipate heat. Compared with the above two surface cooling methods, the cooling capacity is high, which can reduce the temperature. generator size, saves materials and facilitates the manufacturing of large capacity generators, but the generator structure is complex, the copper loss is large, the iron loss and mechanical loss are small, and the total loss is similar.