Wind turbines are complex machines with many subsystems and components. each component performs a function and must be extremely reliable. One of the reasons for failure of components and entire turbines is overheating. In this article, we discuss the methods of cooling in wind turbines, focusing on gearbox coolers and filtration systems.
The sources of heat in the wind turbine
A wind turbine consists of mechanical and electrical parts. The mechanical parts rotate or otherwise move in contact with each other. The result is friction, which heats the contacting surfaces. As far as electrical parts are concerned, heat is generated when current passes through the conducting medium. Heat emission is a form of energy loss.
How wind turbines were cooled
The first wind turbines were not large or powerful, and generated a lot less heat. Natural air cooling was sufficient to dissipate that heat. As power of the turbines increased, this method was not longer enough. At this time, forced air cooling and liquid cooling are the most common cooling techniques. Cooling types section depends on which part of the wind turbine must be cooled: the nacelle, the generator, the distribution cabinet, the tower, the inverter, the transformer or the gearbox.
Forced air cooling
The simplest air cooling can be arranged with sensors, which control the temperature in the wind turbine and the control system, which closes and opens a valve. When a certain temperature is reached, the valve opens and the heat is exchanged with the environment. Since heat emission from separate components may be low, the cooling system is enhanced by a fan.
Some of the advantages of forced cooling systems are simple design, easy operation and servicing and relatively low cost. It should be noted that the efficiency of such heat exchange depends on the environment (subzero temperature, heat, rain etc).
The gearbox cooler is considerably more complicated. It includes gearbox oil, which not only lubricates friction surfaces, but also removes heat. The oil is pumped through the gearbox where it heats up and then goes into a special heat exchanger in the upper portion of the nacelle. The heat exchanger is forced-cooled by air. Cold oil returns to the gearbox for lubrication and cooling. The number of such cycles depends on the current condition of the gearbox oil. The necessity of oil change depends on its projected lifetime (specified by the manufacturer) and laboratory sample test analysis.
Since the oil can accumulate particles of construction materials, moisture and dirt, filters be installed in gearbox coolers. The filter protects not only the pump, but also the gearbox.
Liquid cooling systems include a liquid medium, an air heat exchanger, a pump, valves and controls. Such cooling systems are closed circuits. The cooling liquid used may be water or ethylene glycol solution.
GlobeCore gearbox cooler and filtration systems
GlobeCore designs, manufactures and commissions gearbox cooler and filtration systems on custom orders.
Why ordering from GlobeCore is a good idea:
- we work with all types of wind turbines;
- all custom requirements are considered at the design stage;
- all systems are tested on our site;
- free consultancy.
For more information of wind turbine cooling systems, please contact our experts from the contact section of the web site.