1. Have sufficient insulation performance (sufficiently low conductivity) to prevent generator coil short circuits.
2. Non-corrosive to generator copper wires and internal cooling water system.
3. Impurities present in the cold water of the generator must not settle or scale in the hollow wires, so as not to reduce the cooling effect, cause overheating of the generator bar and cause aging of the isolation and failure.
Product application
Temperature raising requirements and cooling methods of diesel generator sets
1. Closed-loop air cooling
For turbogenerators less than 50,000 kilowatts, a closed-loop air cooling system is often used, and the engine fan is used to blow the heating components to cool them. cool.
2. RefrHydrogen cooling
For generators with a capacity of 50,000 to 600,000 kilowatts, hydrogen cooling is widely used. The heat dissipation performance of hydrogen (purity 99%) is better than that of air, and the heat dissipation effect is good. It can significantly reduce the ventilation friction loss of the engine, thereby greatly improving the efficiency of the generator. Explosion-proof and leak-proof measures must be taken when using hydrogen cooling, which makes the engine structure more complex and increases the consumption and cost of electrode materials.
3. Liquid Cooling
The relative cooling capacity of water is 50 times that of air. To remove the same heat, the flow rate of water required is much lower than that of air. air. Therefore, the use of hollow wires in the coil and the water passagethrough the wires for cooling can significantly reduce the temperature rise of the motor, delay the aging of insulation and extend the life of the motor.
Detailed information
Strictly treated hydrogen for cooling can ensure that the inside of the generator is clean, the ventilation and cooling effect heat dissipation is stable, and there will be no problems caused by dirt.
Hydrogen contains very little oxygen, less than 2%, and does not support combustion. Even if a short circuit fault occurs inside the generator, there is no risk of fire, which can greatly reduce the degree of combustion. Damage caused by fault. In hydrogen there is less noise and the insulating materials are less susceptible to oxidation and corona damage.
The hydrogen in the generator must maintain the specified purity to ensure thehe generator operating performance and avoid explosions. For this purpose, a hydrogen supply device must be installed.
References:
1. Temperature rise requirements
Depending on the insulation of the diesel generator Different grades have different temperature rise requirements. Generally, when the generator is working, the temperature of its stator winding, field winding, iron core, collector ring, etc. will rise. is about 80degrees. If it exceeds 80 degrees, so does the temperature increase. high.
2. Cooling method
NoGenerators of the same type and capacity have different cooling methods. But the cooling fluids used are generally air, hydrogen and water. Taking the turbine synchronous generator as an example, its cooling system is closed and the cooling fluid is recycled.
1. Air cooling. Air cooling adopts fan blowing method, using cold air to blow the ends of the generator set windings, the generator set stator and the rotor to dissipate heat. Cold air absorbs heat and turns into warm air. the rotor starts. After being combined, they are discharged through the iron core air duct and cooled by the chiller. The cooled air is then sent into the generator through thefan to circulate in it to achieve the heat dissipation objective. Medium and small synchronous generators generally use air cooling.
2. Hydrogen cooling. Hydrogen cooling uses hydrogen as a cooling medium. The heat dissipation performance of hydrogen is better than that of air. Most dairy turbine generators use hydrogen cooling.
3. Water cooling. Water cooling adopts the internal double water cooling method of stator and rotor. The external cold water system of the stator water system flows through the water pipe to the water inlet ring installed on the stator base and flows out respectively to each coil through the insulating pipe. After absorbing the heat, it is collected through the insulated water. Hose to installed water outlet ringlaid on the machine base, then discharged into the water system outside the generator for cooling. The rotor water system cooling first enters the water inlet bracket installed on the end of the side shaft of the exciter, and then flows into the center hole of the rotor shaft. rotor, then flows to the water collection tank along several southern holes, and then flows to each coil through the insulating tube. After absorbing the heat, the cold water flows into the water outlet tank through the insulated pipe, and then flows through the drainage hole on the outer edge of the water outlet tank until to the water outlet bracket and is discharged through the main water outlet pipe. Since the heat dissipation performance of water is much higher than that of air and hydrogen, newly built large-scale power generators generally use rwater cooling.