CN102427284B - Wind-driven generator - Google Patents

Abstract

The invention provides a wind power generator, which comprises a motor, a nacelle cover installed on the rear side of the motor, a wind deflector installed on the front side of the motor, and an external heat dissipation shell arranged on the outside of the wind deflector through a supporting structure As well as a circulating fan, the motor includes a motor shaft, a rotor mounted on the shaft, and a stator arranged outside the rotor, the motor is provided with an axial ventilation duct communicating with the front space and the rear space of the motor, and the external heat dissipation A shroud interlayer is formed between the shell and the shroud, and the shroud interlayer communicates with the air gap between the stator and the rotor, and communicates with the axial ventilation channel. The wind generator uses the interlayer structure and the motor shaft as the circulation channel of the cooling medium, and is also a heat dissipation channel for exchanging with the external natural air cooling, thus achieving the purpose of utilizing the external natural air cooling, compact and reasonable layout, and reducing costs.

Description

Wind Turbines

technical field

The invention relates to a wind power generator, in particular to a wind power generator with a ventilation cooling structure.

Background technique

The generator will generate loss during operation, and this part of the loss will be reflected as heat generation. If the heat cannot be dissipated in time, the motor will overheat and the temperature rise will increase, resulting in insulation problems. Therefore, dissipating the heat in the motor in a timely and effective manner is a prerequisite for the normal operation of the motor.

Current generators are mainly cooled by air cooling, water cooling, or air-water mixed cooling.

Water cooling mainly relies on burying water pipes inside the motor or setting water channels on the machine base to cool the motor core with water. The cooling water flows along the water pipes under the action of the water pump, and then enters the motor after heat exchange through the air-water cooler to achieve a cooling cycle. Since the water cooling system needs to bury water pipes in the inner core of the generator, the treatment of the water pipe joints is the key. The water cooling system has high requirements on the production process. If it is not handled properly, water leakage accidents may occur and damage the insulation of the generator.

Air cooling mainly uses air as the cooling medium, and enters the axial ventilation channel or radial ventilation channel inside the motor through the pipeline or the inlet and outlet channels of the motor. After cooling, the hot air will enter the air-to-air cooler, return to the inside of the motor after heat exchange, and complete a cooling cycle. The closed cooling methods that have been adopted in the prior art include a tower cooling method and a nacelle cooling method.

Figure 1 shows the tower cooling method. The tower cooling method can use the tower as a heat dissipation unit, so that the air can fully dissipate heat through the cooling passage provided in the tower. However, the cooling path of the tower cooling method is too long, and the wall thickness of the tower is not conducive to heat dissipation, so the heat dissipation area needs to be large, which makes the heat dissipation channel from the top of the tower to the tower, resulting in large wind resistance, so the fan The power consumption of the electric motor is very large, and at the same time, a high cost is required to make the tower compartment, which increases the cost.

Figure 2 shows the cooling method of the nacelle cover. For the cooling method of the nacelle cover, the cooling is mainly completed by the thermal conductivity of the nacelle cover, while the heat transfer between the nacelle cover and the generator depends on the radiation and heat conduction of the air, so that the heat dissipation is less and the heat dissipation efficiency is low. At the same time, the nacelle cover is entirely made of metal. In order to ensure the strength, the thickness needs to be very thick, which is expensive and has poor thermal conductivity.

If the open-circuit cooling method is used, the air-to-air cooler is not needed, and the outside air is directly introduced into the generator, and the cold air is excluded from the engine room. This advantage is that the temperature of the cooling medium is low, no additional air-to-air cooler is needed, the cost is low, and the structure is simple, but the direct entry of cold air from the outside will bring sand, dust, water, salt spray, etc., which is not good for motor insulation.

In view of the above reasons, there is a need for a wind generator with a properly designed cooling system, so that the temperature rise of the motor of the wind generator can be effectively reduced.

Contents of the invention

In order to solve the problems in the prior art, the invention provides a wind generator with a ventilation cooling structure. The wind generator includes a motor, a nacelle cover installed on the rear side of the motor, a wind deflector installed on the front side of the motor, an external cooling case and a circulation fan arranged on the outside of the wind deflector through a support structure, and the motor includes a motor shaft 1. The rotor installed on the main shaft and the stator arranged on the outside of the rotor, the motor is provided with an axial ventilation channel connecting the front space and the rear space of the motor, and a flow guide is formed between the external heat dissipation shell and the shroud The shroud interlayer communicates with the air gap between the stator and the rotor, and communicates with the axial ventilation channel.

The external heat dissipation shell can be made of materials with thermal conductivity > 80W/mk.

The stator outer surface may protrude from the outer surface of the nacelle cover.

The circulation fan can be arranged at least one of the rear end of the main shaft, inside the main shaft, and the front end of the shroud.

The surface of the external heat dissipation shell may be provided with heat dissipation teeth or folds.

The main shaft may be a hollow structure, and the hollow structure forms the axial ventilation channel.

The axial ventilation channel may be a pipe leading from the shroud and passing through the stator bracket and the rotor bracket.

The outer heat dissipation case can be made of metal with thermal conductivity >80W/mk.

The number of the circulating fans can be one or more connected in series and parallel.

The circulation fan can be an axial fan or a centrifugal fan.

According to the above-mentioned wind power generator, the cooling method of natural air cooling is used, and a sandwich structure is set in the shroud at the impeller. The main shaft of the motor is a hollow shaft. Air-cooled heat dissipation channels are exchanged, thus achieving the purpose of utilizing external natural air-cooling, compact and reasonable layout, and reducing costs. The present invention can be used on direct-drive motors or motors with low speed and large diameter.

Description of drawings

Through the following description of exemplary embodiments in conjunction with the accompanying drawings, the above-mentioned purpose and characteristics of the present invention will become clear and easy to understand, wherein:

Fig. 1 has shown the wind power generator that adopts tower cooling mode in the prior art;

Fig. 2 shows the wind-driven generator that adopts nacelle cover cooling mode in the prior art;

Fig. 3 shows a wind power generator with a ventilation cooling structure according to an embodiment of the present invention.

Among them, the meaning of the label is as follows:

1- the interlayer of the shroud; 2- the shroud at the front of the nacelle; 3- the air gap of the motor; 4- the circulating fan; 5- the nacelle cover; 6- the external cooling shell; Generator rotor; 10-generator stator; 11-generator main shaft; 12-outer surface of generator stator; 13-nacelle interior.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 shows a ventilation cooling structure according to an exemplary embodiment of the present invention.

In the embodiment shown in FIG. 3 , a direct-drive wind power generator is taken as an example for description. As shown in Fig. 3, the wind power generator according to the exemplary embodiment of the present invention includes a motor, a nacelle cover 5 arranged on the rear side of the motor, a wind deflector 2 arranged on the front side of the motor, an external wind deflector 2 arranged on the outside The cooling case 6 and the circulation fan 4 arranged inside the cabin. A wind deflector interlayer 1 is formed between the external heat dissipation shell 6 and the wind deflector 2 . The motor includes a motor main shaft 11, a rotor 9 mounted on the main shaft 11, and a stator 10 arranged on the outside of the rotor 9, and the motor is provided with an axial air duct communicating with the inner space of the nacelle cover 5 and the interlayer 1 of the shroud, The shroud interlayer 1 also communicates with the air gap 3 between the stator and the rotor.

According to the wind power generator of the embodiment of the present invention, the main shaft 11 is a hollow shaft, thereby forming a main shaft air duct, and the main shaft air duct is in fluid communication with the front space and the rear space of the motor.

In addition, the outer surface 12 of the stator 10 protrudes to the outside of the nacelle cover 5, so that the heat dissipation area of the stator 9 is increased, so that the heat dissipation capacity is greatly improved.

The circulation fan 4 can be an axial flow fan or a centrifugal fan, and the number can be one or more connected in series and parallel. In this embodiment, the circulation fan 4 is arranged on the other side of the main shaft 11 opposite to the wind deflector 2 . Apparently, the circulation fan 4 can also be arranged inside the main shaft 11 , or at the front end of the wind deflector 2 .

When the circulating fan 4 is in operation, the cold air in the nacelle cover 5 enters the air gap 3 of the motor under the suction of the circulating fan 4, and after taking away the calorific value of the rotor and a part of the calorific value of the stator, the hot air will enter the Inside the interlayer 2 of the shroud. Since the outer heat dissipation shell 6 of the air deflector 2 can be made of metal with good thermal conductivity (for example, thermal conductivity> 80W/mk), the heat exchange between the hot air and the natural cold air outside is completed through the outer heat dissipation shell 6, and the heat exchange is completed. The cold wind passes through the ventilation channel of the main shaft 11 and returns to the interior 13 of the nacelle after passing through the circulation fan 4, and then passes through the shell of the nacelle cover 5 to perform heat exchange with the outside to complete further heat dissipation and become cold wind, and then circulates under the action of the circulation fan 4. Enter the next cycle.

Since the main heat generation of the motor is concentrated on the stator 10 and the rotor 9, the present invention uses the air gap 3 of the motor and the surface of the stator 12 of the motor as cooling channels to take away most of the heat.

In order to realize the interlayer structure, a structural support is provided in the middle of the air deflector interlayer 1 to connect the front air deflector 2 of the nacelle with the external heat dissipation shell 6 .

In the design, the external heat dissipation shell 6 can also be replaced by non-metallic materials with good heat dissipation performance (for example, thermal conductivity> 80W/mk), and the surface of the external heat dissipation shell 6 can be smooth or have heat dissipation teeth or folds to increase Cooling area.

In addition, the main shaft air passage as the cooling medium passage of the generator can also be replaced by other pipes leading from the nacelle shroud and passing through the stator bracket and the rotor bracket.

Technical scheme of the present invention has following advantage at least:

1. The layout of the heat dissipation channel is reasonable and compact. The air gap of the motor is directly facing the interlayer inlet of the engine room shroud, which avoids the installation of pipes around the motor and makes the entire engine room more compact. At the same time, the entire outlet is distributed around the motor, not just a single one. outlet, so that the air volume distribution is more reasonable, and the temperature rise of the motor is even;

2. The return air path is the main shaft of the generator, and the main shaft is designed as a hollow form. While playing the role of the main shaft, it is also the return air path, which saves the pipe used as the return air path, making the structure compact and the overall design more compact. for simplicity;

3. Using natural air cooling, the hot air inside the motor can be effectively cooled through the good thermal conductivity of the external heat dissipation shell. At the same time, natural air cooling is used to cool the outer surface of the stator, and the heat generated by the motor can be effectively cooled through two ways;

4. The heat dissipation system has an automatic adjustment function. When the external wind is small, the power generated by the motor is small, the calorific value is also low, and the natural wind cooling capacity is also low. When the motor calorific value is high and the external wind speed is high, the heat dissipation is also low. high.

5. Reasonable air path layout makes the cold air in the interlayer of the shroud in the opposite direction to the natural air cooling outside the interlayer of the shroud, forming a counterflow on both sides of the external heat dissipation shell, which has a good heat dissipation effect;

6. The heat dissipation channel and radiator are omitted, and at the same time, the wind resistance is small and the fan power is low, so that the whole cooling system has the characteristics of low cost, high efficiency and less maintenance;

7. The cooling medium circulates inside the engine room without introducing natural wind from the outside, which can avoid the invasion of dust, water and salt spray, and has a good protection effect on the equipment and generator inside the engine room.

While the present invention has been shown and described, it will be understood by those skilled in the art that changes may be made in the exemplary embodiments without departing from the spirit and principles of the invention.

Claims (10)

1. A wind-driven generator, characterized in that, the wind-driven generator comprises a motor, a nacelle cover installed on the rear side of the motor, a wind deflector installed on the front side of the motor, and an outer part arranged on the outside of the wind deflector by a supporting structure A cooling case and a circulating fan, the motor includes a main shaft, a rotor mounted on the main shaft, and a stator arranged outside the rotor, and the motor is provided with an axial ventilation channel connecting the space on the front side of the motor and the space on the rear side of the motor, so A wind deflector interlayer is formed between the external heat dissipation shell and the wind deflector, and the wind deflector interlayer communicates with the air gap between the stator and the rotor, and communicates with the axial ventilation channel. 2. The wind power generator according to claim 1, characterized in that, the external heat dissipation shell is made of a material with a thermal conductivity > 80W/mk. 3. The wind power generator according to claim 1, wherein the outer surface of the stator protrudes from the outer surface of the nacelle. 4. The wind power generator according to claim 1, wherein the circulation fan is arranged at least one of the rear end of the main shaft, inside the main shaft, and the front end of the shroud. 5 . The wind power generator according to claim 1 , wherein heat dissipation teeth or folds are arranged on the surface of the external heat dissipation shell. 6 . 6 . The wind power generator according to any one of claims 1 to 5 , wherein the main shaft is a hollow structure, and the hollow structure forms the axial ventilation channel. 7. The wind power generator according to any one of claims 1 to 5, characterized in that, the axial air passage is a pipe drawn from the shroud and passing through the stator bracket and the rotor bracket. 8. The wind power generator according to any one of claims 1 to 5, characterized in that, the external heat dissipation shell is made of metal with thermal conductivity >80W/mk. 9. The wind power generator according to any one of claims 1 to 5, characterized in that, the circulation fan is one, or a plurality of circulation fans are connected in series and parallel. 10. The wind power generator according to any one of claims 1 to 5, wherein the circulation fan is an axial fan or a centrifugal fan.

Images