WO2018192563A1

WO2018192563A1 - Active air-water coupling cooling system in tower bottom

Info

Publication number: WO2018192563A1
Application number: PCT/CN2018/083851
Authority: WO
Inventors: Nubin WU; Chaoyi XU
Original assignee: Envision Energy (Jiangsu) Co., Ltd.
Priority date: 2017-04-21
Filing date: 2018-04-20
Publication date: 2018-10-25

Abstract

An active air-water coupling cooling system in tower bottom, which realizes an active air cooling circulation in tower bottom by configuring an active air cooling device in tower bottom, and a water cooling circulation by a water cooling device in tower bottom. The active air cooling device is used to control temperature of some heat sources such as the box-type transformer (2) in tower bottom and the frequency converter(4), the water cooling circulation is used to control temperature of the large heat flux density elements in the frequency converter (4), and the air and water cooling circulations can be combined to achieve an accurate control of the ambient temperature and humidity in tower bottom. The air-water coupling cooling system intower bottom features all advantages of air cooling system and water cooling system i.e. stable operation, low cost and effective. The air-water coupling cooling system combines the air cooling system and the water cooling system, and it is significant for onshore high-capacity wind turbine set to operate stably with low cost.

Description

ACTIVE AIR-WATER COUPLING COOLING SYSTEM IN TOWER BOTTOM

TECHNICAL FIELD

The present invention relates to a cooling system in the tower bottom of an onshore high-capacity wind turbine, in particular, an active air-water coupling cooling system in tower bottom.

BACKGROUND

With rapid development of wind power technique, the power of the on-shore wind turbine set and the heat generated therefrom are increasing, wherein most heat is derived from frequency converter and box-type transformer. One of the key issues to guarantee the wind turbine normal operation is how to ensure the heat, which is derived from the heat sources located in the tower bottom, being expelled from the tower.

In the wind turbine set, there are two conventional cooling modes, i.e. air-cooling mode and water-cooling mode, existed in the tower bottom. In a case that a doubly-fed frequency converter has a capacity below 2.5MW or a full power frequency converter has a capacity below 1.5MW, the air-cooling mode is typically used to cool the heat sources located in tower bottom. However, when the frequency converter has a capacity exceeding the foresaid values, the air-cooling mode cannot meet the heat dissipation requirement due to large amount of heat and the water-cooling mode is utilized.

These two conventional cooling modes have their own defects. For air-cooling mode, the whole frequency converter including its power module and reactor is cooled by air, however as the air-cooling mode has a poor heat dissipation while the power module has a large heat flux density, the air-cooling mode cannot meet the heat dissipation requirement of some components, e.g. power module, and seriously affects the performance and life time of the power module with the increase of power level of the frequency converter. Therefore, as the increase of the power level, the water-cooling mode becomes main trend. Currently the power module, the reactors and other components with large heat flux density, which are included in a high-capacity frequency converter, are generally cooled by water. Although water-cooling mode is capable of meeting the heat dissipation requirement, it has low reliability (e.g. liquid cooling system is prone to leak, pipe is prone to corrode) , high cost, and difficulty to maintain.

So far, large capacity wind turbine set becomes main trend of high-capacity on-shore wind turbine set, which requires a more advanced cooling system. In an easy-designed conventional air-cooling system, chimney effect is not sufficient to bring away completely the heat generated by the frequency converter. For high-capacity frequency converter that generates large amount of heat, chimney effect is not sufficient to bring away the heat in tower bottom, which inevitably leads to the overheat of the tower bottom and the frequency converter. For the water-cooling system, its high cost and difficult maintenance is facing the market test.

SUMMARY OF THE INVENTION

Aiming at bottleneck of the cooling, heat dissipation in tower bottom of high-capacity wind turbine set and the problem that wind power industry requires to lower the cost, the present invention provides an active air-water coupling cooling system in tower bottom, which is a tower bottom cooling system with good heat dissipation effect, high reliability and low cost that suitable for high-capacity on-shore generating set.

The technical solution is as follows,

an active air-water coupling cooling system of tower bottom, a vent is configured at the tower bottom, a hole with an active exhaust device therein is configured on the sidewall of the tower, so as to form an bottom-up air cooling circulation in the whole system, and heating elements are arranged on an upper position, along with a water cooling circulation, thereby the air cooling circulation and the water cooling circulation are coupled to cool the heating elements.

Advantages of the present invention are as follows:

The active air-water coupling cooling system in tower bottom according to the present invention realizes an active air cooling circulation in tower bottom by configuring an active air cooling device in tower bottom, and a water cooling circulation by a water cooling device in tower bottom. The active air cooling device is used to control temperature of some heat sources such as the box-type transformer in tower bottom and the frequency converter. The water cooling circulation is used to control temperature of the large heat flux density elements in the frequency converter, and the air and water cooling circulations can be combined to achieve an accurate control of the ambient temperature and humidity in tower bottom. The air-water coupling cooling system in tower bottom features all advantages of air cooling system and water cooling system, i.e. stable operation, low cost and effective. The air-water coupling cooling system combines the air cooling system and the water cooling system, and it is significant for onshore high-capacity wind turbine set to operate stably with low cost.

The active air cooling device is also applicable to control temperature of some other heat sources, with a low heat flux, such as electronic parts, e.g. controllers in the frequency converter and/or electronic parts of other equipment and/or individual controllers positioned in the tower bottom area.

Preferably, the present active air-water coupling cooling system in tower bottom, a transformer and a water chilling unit are positioned in tower bottom, a frequency converter is positioned on the second floor platform or above in the tower, water cooling heat dissipation unit is located outside the tower, an air hole together with a ventilator therein is arranged on the sidewall of the tower, and a vent is arranged below the first floor platform in tower bottom.

In the active air cooling circulation, external cool air is sucked into tower via the vent in tower bottom and the tower door air inlet, then through the transformer by its own fan, to cool the transformer; this air, together with some cool air that did not go through the transformer, is sucked into the frequency converter by its own fan, to cool the air cooling module in frequency converter, then the air is heated and expelled from the frequency converter, and exhausted outside the tower via the hole and ventilator, whereby the whole active air cooling circulation is completed;

In water cooling circulation, high temperature coolant is pumped in a pump station in the water chilling unit to the water cooling heat dissipation unit to be cooled, then the cooling water that has been cooled enters the frequency converter via the water chilling unit to cool the water cooling module in the frequency converter, whereby the coolant is heated. Subsequently, the coolant is pumped to the water cooling heat dissipation unit via the pump station, and the circulation is completed.

This water cooling circuit allows for effective water cooling of the parts that emit significant of excessive heat, which ensures targeted and effective cooling thereof.

In the active air cooling circulation, when cool ambient air is sucked into tower via the vent in tower bottom and the tower door air inlet, the air may be rather cool and the air humidity may during certain seasons or during rainy or foggy weather conditions even be below the saturation point. This will create problems when passing the ambient cooling air through air cooled parts, because the humidity present in the ambient air can condense on the electronic components and cause damage to the electronic components. This problem is elegantly solved in a surprisingly simple manner by conditioning the air inside the tower bottom.

Thus the hybrid water-air cooling system according to the present invention thus provides accurate temperature control of the cooling air and elegantly solves the problems mentioned above in relation to provide effective low cost cooling and reduce cost for running and reduce the risk for damages in components caused by excessive heat. Further, the present invention reduces maintenance and/or repair costs.

The conditioning of the cooling air is provided by heating a part of the ambient air in a first room, e.g. at the lower level, by passing the cooling air through the transformer by its own fan, to cool the transformer and/or other components with a low to medium heat flux (other than the frequency converter) that are present in the tower bottom. Thereby this airstream is heated. The heated air is then mixed with some cool ambient air that did not go through the transformer. This increases the temperature of the ambient air slightly whereby the cooling air humidity is lowered to a level above the saturation point (with respect to air humidity) .

In addition, the chilling unit that is installed in the tower bottom also assists in heating of the cooling air, and the cooling air inside the tower assists in cooling the liquid coolant/water that passes through the chilling unit. This further optimizes the interaction between the air cooling part and the liquid coolant part of the air/water hybrid cooling system according to the present invention.

Particulate filters may be installed at the air inlets that provide air into the interior of the tower. The particulate filters are conventional mechanical particulate filters, such as filter cloth, a filter cassette, a hepa filter or a somewhat larger filtering equipment using filter cloths, hoses similar low cost filtering means. Alternatively, an electrostatic filter may be used.

This air conditioned cooling air is then sucked into the second room where the frequency converter is placed, and is provided to the air cooled part (s) of the frequency converter by its own fan (s) , where low heat emitting parts, e.g. excessive heat from electronics, such as controllers are cooled by air cooling.

The air is expelled from the frequency converter by the fan or fans which are preferably arranged at air outlets and/or air inlets of the frequency converter’s cabinets that surround the other components (other than the large heat flux density components.

Electronic components present in controllers etc. are usually stable in their performance in a rather broad temperature interval and may be stable in operation at temperatures up to 40-45 ℃ without any significant loss in performance. At higher temperatures, it is necessary to provide cooling to ensure stable and optimal operation and to lower the risk of damage to these electronic components.

The degree of air cooling is simply controlled by means of detecting the temperature inside the tower bottom, such as at the entry into the frequency converter, and by controlling the fan in a simple on/off manner, where the fan is turned off below a certain temperature, e.g. 40 ℃ and turned on, when the temperature is above a second setpoint, e.g. 45 ℃. Alternatively, the speed of the fan at the air cooling can be controlled so as to increase fan rotational speed at increasing temperatures and decreasing fan speed at lower temperatures, e.g. in curved manner or in stepwise manner.

Preferably the large heat flux density elements in the frequency converter are located in an individual cabinet and provided with a water cooling module, and other elements are arranged in another cabinet; the frequency converter is provided with an air cooling module.

This allow for individual cooling of the relevant components of the frequency converter arranged in the tower bottom, i.e. the large heat flux density components by means of water cooling while allowing that other components with a low heat flux density, such as electronics, controllers, etc. are air cooled.

The large heat flux density elements are provided with the water cooling module which comprises a water pipe through the large heat flux density elements, to cool down the large heat flux density elements by water cooling heat dissipation unit located outside the tower and the water inlet and outlet pipe.

This allows for targeted cooling of the specific parts of the frequency converter.

The cooling air may also pass through the part of the frequency converter, that is water cooled as discussed further above, in a similar manner using a fan at the inlet or outlet of the individual cabinet of the large heat flux density components. This further improves cooling thereof and reduces the risk of condensation around the water cooling system or inside the frequency converter cabinet or system.

Preferably, the air cooling module comprises openings configured at the bottom of the two cabinets, and fans configured in the upper portion of the two cabinets; the external fresh air is guided into the frequency converter by the fans via the openings, and the large heat flux density elements and the other heating elements are cooled by air, then the air is exhausted by the fans.

This allows for the air to be sucked through the cabinets from the inlet openings to the outlet openings of the cabinets by means of the fans provided at the outlets. Further the air cooling of the cabinet surrounding the water cooled parts of the frequency converter effectively prevents any condensation caused by the water cooling system.

The cooling air is expelled from to tower interior to the surroundings via an air outlet. The air outlet is preferably provided with a ventilator so as to expel the air.

The above mentioned drawbacks of the prior art and the above mentioned effects of the present invention are also solved by means of a method for providing an active air-water coupling cooling system in tower bottom, wherein a transformer and a water chilling unit are positioned in the tower bottom, a tower door air inlet is located in the tower bottom, a frequency converter is positioned on a second floor platform or above in the tower, a water cooling heat dissipation unit is located outside the tower, an air outlet together with a ventilator therein is arranged on the sidewall of the tower, and an air inlet is arranged below a first floor platform in tower bottom. The method comprises the following steps of operating of the active air cooling circulation, wherein

external cool air is sucked into tower via the vent in tower bottom and the tower door air inlet, then through the transformer by its own fan, to cool the transformer;

this air, together with some cool air that did not go through the transformer, is mixed and sucked into the frequency converter by its own fan, to cool the air cooling module in frequency converter,

then the air is heated and expelled from the frequency converter, and exhausted outside the tower via the hole and ventilator, whereby the whole active air cooling circulation is completed. In addition, in the water cooling circulation path, a high temperature coolant is pumped in a pump station in the water chilling unit, to the water cooling heat dissipation unit to be cooled, then the cooling water that has been cooled enters the frequency converter via the water chilling unit to cool the water cooling module in the frequency converter, subsequently the coolant is heated and is pumped to the water cooling heat dissipation unit via the pump station, and the circulation is completed.

Preferably, the cooling air also pass through the part of the frequency converter, that is water cooled by means of a fan at the inlet or outlet of the individual cabinet of the large heat flux density components.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is an operation principle schematic view of an active air-water coupling cooling system in tower bottom according to the invention;

Fig. 2 is a structural schematic view of a cooling system inside a frequency converter according to the invention;

Fig. 3 is a top view of the frequency converter according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

An active air-water coupling cooling system in tower bottom includes an active air cooling circulation and a water cooling circulation. A box-type transformer in tower bottom is cooled by an active air-cooling and a frequency converter is cooled by an active air-cooling system coupled with external water-cooling system. An active air-cooling fan can be controlled to turn-on or turn off by the ambient temperature within tower bottom, to control the temperature of the box-type transformer, the frequency converter and the tower bottom.

Fig. 1 shows an operation principle of an active air-water coupling cooling system in tower bottom, a transformer 2 and a water chilling unit 3 are positioned on the first floor platform in tower bottom, a tower door air inlet 7 is located in bottom of the tower, a frequency converter 4 is positioned on the second floor platform or above in the tower, a water cooling heat dissipation unit 6 is located outside the tower, a hole and a ventilator 5 therein are arranged on the sidewall of the tower, a vent 1 is arranged below the first floor platform in tower bottom.

In the active air cooling circulation, external fresh air is sucked into the tower via the vent 1 in tower bottom and the tower door air inlet 7, then through the transformer 2 by its own fan, to cool the transformer 2; this air, together with some fresh air that did not go through the transformer 2, is sucked into the frequency converter 4 by its own fan, to cool the air cooling module in frequency converter 4, subsequently the heated air is expelled from the frequency converter 4, and exhausted outside the tower via the hole and ventilator 5, whereby the whole active air cooling circulation is completed.

In the water cooling circulation, high temperature coolant is pumped in a pump station in the water chilling unit 3, to the water cooling heat dissipation unit 6 to be cooled, then the cooling water that had been cooled enters the frequency converter 4 via the water chilling unit 3 to cool the water cooling module in the frequency converter 4, subsequently the heated coolant is again pumped to the water cooling heat dissipation unit 6 via the pump station, then the circulation is completed.

Fig. 2 shows a cooling system inside a frequency converter, comprising an air cooling module and a water cooling module. 80%of the total amount of heat is contributed by the filter elements and/or transistors in power module, the filter elements have small size but large heat flux density, as the so-called large heat flux density elements. The large heat flux density elements 8 are located in an individual cabinet, and other elements are arranged in another cabinet. The large heat flux density elements 8 adopt water cooling mode mainly because of the large heat flux density. The water cooling module comprises a water pipe through the large heat flux density elements 8, to cool down the large heat flux density elements 8 by water cooling heat dissipation unit 6 located outside the tower and the water inlet and outlet pipes 12.

The other heating elements adopt air cooling mode. The air cooling module comprises openings 11 configured at the bottom of the two cabinets, and fans 10 configured in the upper portion of the two cabinets. The external fresh air is guided into the frequency converter by the fans 10 via the openings 11, as the top view of the frequency converter shown in fig. 3, and the other heating elements 9 and the large heat flux density elements 8 are cooled by air, then the air is exhausted by the fans 10.

The present active air-water coupling cooling system in tower bottom changes the cooling mode of the frequency converter 4 from a single mode (air cooling mode or water cooling mode) to an active air-water coupling cooling mode, the power element kits in the frequency converter 4 are cooled by water cooling circulation and other heat sources are cooled by active air cooling circulation. As there are two heat dissipation types, which can be operated in any combination depends on different temperatures, thereby the high load working time of the heat dissipation elements is lowered, the maintenance rate is also reduced.

The operation of the ventilator 5 depends on the inlet air temperature of frequency converter 4. When the inlet air temperature reaches above 45℃, the ventilator 5 turns on, while the inlet air temperature is below 40℃, the ventilator 5 turns off.

Claims

An active air-water coupling cooling system in tower bottom, characterised in that, a vent is configured at the tower bottom, a hole with an active exhaust device therein is configured on the sidewall of the tower, so as to form an bottom-up air cooling circulation in the whole system, and heating elements are arranged on an upper position, along with a water cooling circulation, thereby the air cooling circulation and the water cooling circulation are coupled to cool the heating elements.
An active air-water coupling cooling system in tower bottom according to claim 1, characterised in that, a transformer and a water chilling unit are positioned in the tower bottom, a tower door air inlet is located in the tower bottom, a frequency converter is positioned on a second floor platform or above in the tower, water cooling heat dissipation unit is located outside the tower, an air hole together with a ventilator therein is arranged on the sidewall of the tower, and a vent is arranged below a first floor platform in tower bottom;

in the active air cooling circulation, external cool air is sucked into tower via the vent in tower bottom and the tower door air inlet, then through the transformer by its own fan, to cool the transformer; this air, together with some cool air that did not go through the transformer, is sucked into the frequency converter by its own fan, to cool the air cooling module in frequency converter, then the air is heated and expelled from the frequency converter, and exhausted outside the tower via the hole and ventilator, whereby the whole active air cooling circulation is completed;

in the water cooling circulation, high temperature coolant is pumped in a pump station in the water chilling unit, to the water cooling heat dissipation unit to be cooled, then the cooling water that has been cooled enters the frequency converter via the water chilling unit to cool the water cooling module in the frequency converter, subsequently the coolant is heated and is pumped to the water cooling heat dissipation unit via the pump station, and the circulation is completed.
An active air-water coupling cooling system in tower bottom according to claim 2, characterised in that large heat flux density elements in the frequency converter are located in an individual cabinet and provided with a water cooling module, and other elements are arranged in another cabinet; the frequency converter is provided with an air cooling module.
An active air-water coupling cooling system in tower bottom according to claim 3, characterised in that the large heat flux density elements are provided with the water cooling module which comprises a water pipe through the large heat flux density elements, to cool down the large heat flux density elements by water cooling heat dissipation unit located outside the tower and the water inlet and outlet pipe.
An active air-water coupling cooling system in tower bottom according to claim 3 or 4, characterised in that the air cooling module comprises openings configured at the bottom of the two cabinets, and fans configured in the upper portion of the two cabinets; the external fresh air is guided into the frequency converter by the fans via the openings, and the large heat flux density elements and the other heating elements are cooled by air, then the air is exhausted by the fans.
A method for providing an active air-water coupling cooling system in tower bottom, wherein a transformer and a water chilling unit are positioned in the tower bottom, a tower door air inlet is located in the tower bottom, a frequency converter is positioned on a second floor platform or above in the tower, a water cooling heat dissipation unit is located outside the tower, an air outlet together with a ventilator therein is arranged on the sidewall of the tower, and an air inlet is arranged below a first floor platform in tower bottom;

wherein the method comprises the following steps of operating of the active air cooling circulation,

-external cool air is sucked into tower via the vent in tower bottom and the tower door air inlet, then through the transformer by its own fan, to cool the transformer;

-this air, together with some cool air that did not go through the transformer, is mixed and sucked into the frequency converter by its own fan, to cool the air cooling module in frequency converter,

then the air is heated and expelled from the frequency converter, and exhausted outside the tower via the hole and ventilator, whereby the whole active air cooling circulation is completed;

and wherein

in the water cooling circulation path, a high temperature coolant is pumped in a pump station in the water chilling unit, to the water cooling heat dissipation unit to be cooled, then the cooling water that has been cooled enters the frequency converter via the water chilling unit to cool the water cooling module in the frequency converter, subsequently the coolant is heated and is pumped to the water cooling heat dissipation unit via the pump station, and the circulation is completed.
A method according to claim 6, wherein the cooling air also pass through the part of the frequency converter, that is water cooled by means of a fan at the inlet or outlet of the individual cabinet of the large heat flux density components.