Summary of heat dissipation of wind turbine generator set

First of all, in the early stage of the development of wind power industry, the heat dissipation problem does not need to be considered too much. In addition, at that time, converter cabinets, box transformers and other equipment were often on the ground next to the fan. With the development of wind power industry, in order to reduce the cost and project cost, the equipment originally placed outside the tower began to move slowly into the tower. When the capacity of the unit is still small, the converter cabinet and electric control cabinet in the unit are cooled by natural wind or forced wind, and the heat is directly discharged into the unit, so the whole unit has no cooling system. For example, the converter cabinet and electric control cabinet at the bottom of the tower directly discharge hot air into the tower. But in this case, there will still be a natural stack effect, which can promote the air flow inside the fan.

With the increasing capacity of a single wind turbine, more and more heat is generated by the heating components in the turbine. Although people pay more attention to the heat dissipation of various components in the unit and strengthen the heat dissipation design, although the heat is discharged from the cabinet, the internal environmental temperature of the unit continues to rise, and the heat dissipation environment in which the cabinet is located continues to be bad, which eventually leads to overheating.

In this case, people began to pay attention to the temperature control of the unit environment.

In the patent of "cooling system of wind turbine and wind generator", it is proposed to use the gap between the static and dynamic joints of the nose, such as the gap between the blade root and the hub cover. The airflow enters the hub from the gap at the blade root, passes down the tower through the base, and finally comes out from the tower wall at the bottom of the tower. The exhaust fan is installed at the air outlet to provide power for the air flow. The advantage of this scheme is that high-altitude air with lower temperature than the ground can be used to cool the heating components inside the fan. At present, when the fan unit tends to be large-scale and the heating power is increasing, it is more and more urgent to find a cheap cold source to cool the heating components of the unit. The temperature of high-altitude cold air is lower than that of near-surface air, which makes it have a higher cost-effective advantage as a cold source. However, the disadvantage is that the airflow in the tower is against stack effect, and the airflow in the tower is easy to form vortex. In order to achieve the design goal, it is necessary to increase the power of the exhaust fan at the bottom of the tower and set up multiple exhaust fans in the wind path to realize intermediate relay.

In addition, there is a problem that it is difficult to filter the air entering from the gap between the blade root and the hub, and it is difficult to control the internal environment of the unit in areas with sandstorms or high salt fog at sea. Because this scheme has no humidity control function, it can only be applied to areas with dry air.

In order to solve the above problems, the patent "wind turbine internal environment control system" changed the airflow direction of the above scheme, and changed it into air intake from the bottom of the tower near the ground, ascending the tower, entering the nose, and then coming out from the gap between the blade root and the hub. The exhaust fan on the side wall of the tower bottom is changed into a blower. In this way, the heat generated by the blower is also brought into the unit, and the air temperature near the ground is higher than that at high altitude, so it is undoubtedly worse to add the heat generated by the blower. In order to make up for the shortage of cold source, a central air conditioner is installed in the unit as a supplement. This undoubtedly increases the acquisition cost of cold source. Although the addition of central air conditioning makes this scheme have the ability to dehumidify the unit environment, the dehumidification ability of air conditioning is still a drop in the bucket compared with the air inlet. This scheme still limits its application scope and determines that it is not suitable for high humidity areas. The high cost of cold source acquisition also determines the high operating cost.