The main fuel for diesel engines is diesel. Light diesel is used in high-speed diesel engines. Heavy diesel is used in medium and low speed diesel engines, and heavy fuel oil is used in large scale low speed diesel engines.
1 Air cooling uses wind as the cooling fluid. cooling and directly uses the wind for. cool the diesel generator. Water cooling uses water as a cooling medium. Then the heat is dissipated through a water tank and an electric fan. There isn't much difference in usage. suitable for plateaus or places where water is scarce or cold. You don't need to consider adding water, boiling point, freezing and other issues; When water cooling is used on trays, the boiling point of water decreases and it is easy to do so. freeze during arnot in high altitude locations. The boiling point and freezing point can be improved by adding a certain proportion of additives. In addition, the heat transfer performance of water is better. In fact, there are virtually no constraints on environmental conditions when using them.
2. The biggest advantage of air-cooled unit is its simple structure, easy maintenance, low failure rate, good starting performance, small amount of air required, easier shutdown, high thermal efficiency and its low fan power. consumption and low fuel consumption. Low, there is no risk of frost cracking or overheating and boiling, but it is subject to thermal load and mechanical load constraints, and the power is generally relatively small. The water cooling system problem accounts for more thanhalf of the total fault share of diesel generator set. Air-cooled units do better. The biggest advantage of a water-cooled generator is its high efficiency and rapid cooling. At the same time, the power conversion rate of the body itself is improved.
3. The air-cooled cylinder block and cylinder liner are integrated or assembled into one without gap. The interior is the working area where the piston slides, and the exterior is densely distributed heat sinks in a uniform and orderly manner, which are usually die-cast with materials with high thermal conductivity. The working heat of the piston is directly transmitted through the cylinder and is. carried away by the air flowing between the heat sinks, this method is generally used on two-stroke engines; the water-cooled engine has a complex cooling water channel (cooling linerdry cylinder) cast in the cylinder, or a cooling water channel (wet cylinder liner) is formed with the cylinder liner and the piston is in the cylinder liner. During operation, heat is transferred to the cooling water in the water channel through the cylinder liner for cooling. This method is generally used on four-stroke engines. Air-cooled generators are generally low power and do not generate large amounts of heat, so air cooling is sufficient; High power generators require water cooling due to their high calorific value.
4. The air-cooled generator from the generator manufacturer has high thermal efficiency and economy. Since the air-cooled diesel generator transfers less heat to the air, its cooling air volume is only about 2/3 ofthat of the water-cooled diesel engine. This is because when the gas temperature of an air-cooled diesel engine is constant, the higher the cylinder wall temperature, the less heat the diesel engine dissipates into the air, the higher the thermal efficiency, the lower the fuel consumption, the better. the economy. Generally, the cylinder wall temperature of an air-cooled diesel engine is tens of degrees higher than that of a water-cooled diesel engine, so its thermal efficiency is higher than that of a diesel engine. water cooled.
5. Air-cooled generators from the generator manufacturer have a long service life. The air-cooled diesel engine heats up quickly due to the high temperature of the cylinder walls, which greatly avoids acid corrosion and wear. the duration of operation of the diesel engine below the dew point. Therefore, the pAir-cooled diesel engine parts exhibit less corrosion, cavitation and rust, and there is no inconvenience of scale accumulation in the cylinder cover and radiator. Long service life. It can be seen that the air-cooled diesel engine has good drivability, short warm-up time and simple suggestions, eliminating the burden of increasing cooling water and releasing cooling water, and There is no need to worry about damage accidents of the cylinder block, cylinder head, radiator, etc. due to frost cracking, so it has high reliability in use, few defects, long service life, easy protection and maintenance.
What are the common cooling methods for turbogenerators?
Air coolers are installed for cooling purposes.
Principle
Due to the loss of copper and iron loWhen the generator is working, the temperature of the iron core and coil will gradually increase. In order to reduce the aging rate of the coil insulation and prolong its service life, the temperature of the coil should not exceed a certain value, such as 100°C. Therefore, measures should be taken to discharge the heat generated by the coil and the iron core in time to maintain the temperature of the coil insulation not exceeding the specified value. The most commonly used cooling methods include air cooling, hydrogen cooling, and water cooling. Although the effect of air cooling is poor, the air cooling equipment is simple and reliable, so it is widely used in medium and small generator sets.
The function of the cooler
The air cooler uses cooling water to coolcools the higher temperature air coming out of the generator, then sends it into the generator. In fact, when the generator operates, the heat generated is removed by the cooling water, and the air only acts as a fluid.
Due to the poor air cooling effect, large generators often use hydrogen cooling and water cooling with good cooling effect.
Commonly used cooling methods for turbogenerators are:
(1) Air cooling. It is divided into open air cooling and closed circulation air cooling. So-called open-air cooling consists of the fact that in ordinary small generators the generator fan draws cold air into the engine from the factory building, cools each part, and then exhausts it out of the machine . Closed cycle air cooling is used in heat generatorslarge and medium size. After the cooling air exits the generator, it is conducted under the machine pit. After being cooled by a set of air coolers, it is driven into the engine by one. fan. This air always circulates inside to keep the machine clean.
(2) Water cooling. Generally, it is internal double water cooling, that is, the conductors of the stator winding and the rotor excitation winding are hollow, the water from Cooling passes inside the conductors and the stator bore is always cooled by air. Although the cooling efficiency is high, the interior of the driver is prone to scaling and clogging.
(3) Hydrogen cooling. It is divided into two cooling methods: external hydrogen cooling and hydrogen water cooling. External hydrogen cooling is idealnticle to air cooling, except the cooling fluid changes from air to hydrogen, but the hydrogen cooler is inside the machine. The difference between water-hydrogen cooling and hydrogen cooling is that the cooling water passes inside the stator winding conductor, and the rest is the same as external hydrogen cooling.