CN110821762A - A kind of air heat deicing device for wind turbine blades - Google Patents

Abstract

The invention discloses an air-heat deicing device for wind turbine blades, comprising: a hot air output device arranged in a nacelle at the top of a wind turbine tower; a single-layer ventilation duct connected to an air outlet of the hot air output device, the single The layer ventilation duct is used to extend through the middle channel of the fan generator to the fan hub; the single-layer multi-channel rotary joint is arranged in the fan hub; the blade ventilation duct is arranged in the inner cavity of the fan blade; the single-layer multi-channel The rotary joints are respectively connected to the single-layer ventilation duct and the blade ventilation duct. The air-heat deicing device for wind turbine blades provided by the invention has high reliability, no risk of lightning damage, strong maintainability and low maintenance cost, and can safely, economically and conveniently complete deicing of fan blades.

Description

A kind of air heat deicing device for wind turbine blades

technical field

The invention relates to the technical field of wind power generation, in particular to a gas-heat deicing device for blades of wind turbines.

Background technique

Wind power generation has become an important energy structure in my country. With the rapid update of wind power generation technology, the diameter of the wind rotor has increased rapidly. The traditional low wind speed areas in the central and southern regions of my country have become areas where various wind power developers compete for development. In Yun, Gui, Hunan, Hubei, Jiangxi and other provinces in this region, due to the humid winter climate, frequent freezing rain, rime and other weather, wind turbines generally have the problem of freezing in winter.

Wind power generation operates in cold climates, and the blade of the fan is prone to the phenomenon of blade freezing. This phenomenon will have the following hazards: blade freezing will damage the original aerodynamic characteristics of the blade to varying degrees, reduce power output, and in severe cases It needs to be forced to shut down, thereby reducing the power generation of the unit. When the blades freeze, it will increase the extra load of the wind turbine, and the long-term load operation will reduce the service life of the wind turbine. When the blade freezes, the ice cubes will be thrown off, and there is a risk of endangering the safety of people and equipment.

However, according to the IEA (International Energy Agency) classification of the global freezing area, the most severely icing areas in the world are mainly concentrated in Europe. Therefore, for the promotion of wind turbine deicing technology in the domestic market, it must have the advantage of low cost, otherwise it will be difficult to market.

According to the existing data, the active deicing technology of fan blades is mainly divided into two categories: electric heating deicing and gas heating deicing. Electric heating deicing mainly coats a layer of electric heating medium on the outer surface of the blade, while gas heating deicing mainly installs a heating system (heater + blower) in the inner cavity of the blade, and transports the air to the inner cavity of the blade after heating. The invention belongs to a kind of gas heating deicing technology.

The technical advantages of gas heating deicing are high reliability, no risk of lightning damage, strong maintainability of the entire system, and low maintenance costs.

The patent applied for by German Senvian Co., Ltd., the publication number CN105683566A, is "rotor blade de-icing", which is a ventilation duct that delivers hot air by installing a heating device in the blade root or in the hub or nacelle near the blade root. The heater extends through the baffle at the root of the blade to the tip of the blade, and the heating device and the inner cavity of the blade form an integral closed space. Air circulation is formed in this closed space, and openings are arranged on the hot air ventilation duct inside the blade to improve the heat conversion efficiency, so as to achieve the purpose of deicing the heating blade. The disadvantage of this method is that the heater can only heat one rotor blade during operation, which is very unfavorable for the dynamic deicing of the fan during operation, because in freezing climate conditions, the three blades of the fan (currently the high-power horizontal shaft Wind turbines basically use three blades) will freeze at the same time. If only one of the blades is deiced and operated, it is easy to cause the imbalance of the three rotor blades. In severe cases, the vibration of the fan may increase and cause a collapse accident. In addition, this method must supply power to the heater through the hub slip ring, which requires relatively high power level of the slip ring, and the cost is relatively high.

The patent applied by Chongqing University, the publication number CN102003353A published the "Large Wind Turbine Blade Deicing Method", this method adopts the combination of air-heat deicing and blade type flutter to deicing the blade: the heating system is all installed on the blade Inside, each blade forms a closed and independent space. The blade is heated first, and by detecting the melting state of the ice covered on the surface of the blade, and then by controlling the pitch and yaw speed of the fan to form a flutter effect of the unit caused by acceleration first and then deceleration. Deicing leaves. The disadvantage of this method is: the flutter of the unit may cause mechanical damage to related components (such as yaw and pitch reducer, yaw motor, pitch motor, etc.) and reduce the service life; the heater is installed inside the blade, and the three The heater rotates with the impeller, and there is a risk of falling off, and the power supply of the heater must pass through the slip ring of the hub, which is costly. All in all, in addition to saving energy and improving the deicing effect, this method has high overall cost, low safety and reliability of the heater, and unit flutter that affects the service life of related components.

The patent applied by Shenzhen Branch of China Resources Power Investment Co., Ltd., the publication number CN107676233A, "A Wind Turbine Generator and Its Blade De-icing System" (Note: This patent belongs to the company and my own invention), the invention is adopted in the engine room. The heating system is installed to transmit the hot air to the inner cavity of the blade through the double-layer ventilation duct of the engine room through the multi-channel rotary joint, and the inner cavity of the three blades is formed into a closed space for overall heating to achieve the purpose of deicing the blade. However, the inner layer of the double-layer ventilation duct used in this invention is used to supply air to the blades, and the outer layer of the duct is used to return air to the interior of the engine room; due to the narrow space between the engine room and the hub, the design and manufacture of the double-layered conveying pipeline is very difficult, especially Due to the need to ensure a certain ventilation flow, the double-layer multi-channel rotary joint is very bulky, which is not conducive to installation and construction. The size of the inner pipe is limited, which limits the air supply flow, resulting in poor heating and deicing effect. In addition, the design, manufacture and construction costs of the double-layer conveying pipeline and the double-layer multi-channel rotary joint adopted in the invention are relatively high, which is not conducive to market promotion.

Therefore, how to safely, economically and conveniently deicing the blades of wind turbines has become a technical problem to be solved by those skilled in the art.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a gas heat deicing device for wind turbine blades. The device has high reliability, stable and safe operation, low operation and maintenance cost, and can complete the deicing of fan blades safely, economically and conveniently.

In order to achieve the above purpose, the present invention provides an air-heat deicing device for wind turbine blades, comprising:

Hot air output device installed in the engine room at the top of the wind turbine tower;

a single-layer ventilation duct connected to the air outlet of the hot air output device, the single-layer ventilation duct is used to extend to the fan hub through the intermediate channel of the fan generator;

A single-layer multi-channel rotary joint set in the fan hub;

Blade ventilation ducts arranged in the inner cavity of the fan blade;

The single-layer multi-channel rotary joint is respectively connected to the single-layer ventilation duct and the blade ventilation duct.

Optionally, the hot air output device includes a heater and a blower connected to an air inlet of the heater.

Optionally, the single-layer ventilation duct is a heat-resistant hose.

Optionally, the single-layer ventilation duct is detachably connected to the heater and the single-layer multi-channel rotary joint.

Optionally, the periphery of the heater is provided with an insulating bag for insulating the cabin space behind the heater.

Optionally, a backflow prevention baffle is provided at the air outlet of the blade ventilation duct, and the backflow prevention baffle is used to be fixed between the blade web of the fan blade and the blade shell.

Optionally, a first temperature sensor is arranged inside the single-layer ventilation duct, and a second temperature sensor is arranged between the outside of the single-layer ventilation duct and the middle channel of the fan generator to detect the return air temperature, so the first temperature sensor and the second temperature sensor are connected to the temperature control mechanism of the heater;

When the first temperature sensor detects that the outlet air temperature is lower than the first preset value, the temperature control mechanism controls the heater to increase the output power; when the second temperature sensor detects that the return air temperature is higher than At the second preset value, the temperature control mechanism controls the heater to reduce the output power.

Optionally, further comprising a third temperature sensor arranged on the outer layer of the fan blade, the third temperature sensor being connected to the heater;

When the third temperature sensor detects that the temperature of the fan blade is lower than a third preset value, the heater starts heating.

Compared with the above background technology, the wind turbine blade air heat output device provided by the present invention is arranged in the nacelle at the top of the wind turbine tower through the single-layer ventilation duct, the single-layer multi-channel rotary joint and the blade ventilation duct. The hot air is delivered to the inside of the fan blades for air-heat deicing, which avoids the risk of lightning strikes caused by the electric heating mechanism in the fan blades, improves the safety performance, and can de-icing all the fan blades at the same time, avoiding uneven de-icing of the fan blades and reducing the blade stability.

More importantly, single-layer ventilation ducts and single-layer multi-channel rotary joints are used to facilitate duct design. The size of the single-layer ventilation ducts can be arranged in the limited space in the middle channel of the fan generator, and ensure the delivery To meet the demand of air flow, the hot air passes through the single-layer ventilation duct in turn, reducing the operation and maintenance cost of the air-heat deicing device; the single-layer multi-channel rotary joint and the blade ventilation ducts respectively set in multiple fan blades, the return air can pass through the fan blades The open manhole cover at the root and the gap between the single-layer ventilation duct and the intermediate channel return to the engine room to heat the engine room, which ensures the high temperature of the engine room during the freezing period, which is beneficial to improve the grease in the hub and the engine room. Lubrication effect. The single-layer ventilation duct and the single-layer multi-channel rotary joint reduce the retrofit cost of the air-heat deicing device; the air-heat de-icing device outputs hot air to the fan blades and the engine room through the hot air output device, which can realize air-heat deicing and hot air. The output device is arranged in the engine room to avoid being damaged by lightning strikes in the fan blade, and deicing is economical, convenient and safe.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

1 is a schematic diagram of an air-heat deicing device for wind turbine blades provided by an embodiment of the invention;

FIG. 2 is a schematic diagram of the arrangement of blade ventilation ducts in the fan blade.

in:

1-tower, 2-engine room, 3-generator, 4-hub, 5-fan blade, 6-blade web, 7-blower, 8-heater, 9-single-layer ventilation duct, 10-single-layer multi-layer Channel rotary joint, 11-blade ventilation duct, 12-backflow prevention baffle.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to make those skilled in the art better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram of an air-heat deicing device for wind turbine blades provided by an embodiment of the invention, and FIG. 2 is a schematic diagram of the arrangement of blade ventilation ducts in a fan blade. flow.

The air-heat deicing device for wind turbine blades provided by the present invention includes a hot air output device, a single-layer ventilation duct 9 , a single-layer multi-channel rotary joint 10 and a blade ventilation duct 11 . The hot air output device is used to be arranged in the nacelle 2 of the wind turbine, and the nacelle 2 is located at the top of the tower 1; the single-layer ventilation duct 9 extends through the middle channel of the fan generator 3 to the hub 4, and the single-layer multi-channel rotates The joint 10 is arranged in the hub 4, and plays the role of connecting the single-layer ventilation duct 9 and the blade ventilation duct 11, and can complete the transportation of hot air in a rotating state, and realize the deicing of the fan blade 5 in the operating state, which is very convenient; the blade ventilation duct 11 then outputs the hot air to the inside of the blower blade 5, which plays the role of heating and deicing the blower blade 5. Due to the limited space in the middle passage of the fan-generator 3, the single-layer passage can not only meet the needs of blade deicing and air supply, but also facilitate the rotating air supply. The gap between the passages is used to return air to heat the interior of the engine room 2 to ensure the lubricating performance of the lubricating oil.

The air-heat deicing device for wind turbine blades provided by the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

In a specific embodiment provided by the present invention, the hot air output device specifically adopts a combination of a heater 8 and a blower 7, the air is heated by the heater 8, and the blower 7 is connected to the air inlet of the heater 8, and the single-layer air is heated by the heater 8. The ventilation duct 9 is connected to the air outlet of the heater 8, and the blower 7 provides sufficient power for the output of the hot air, and at the same time plays the role of increasing the air flow. The heater 8 adopts a common electric heating type heater 8, and the heater 8 is provided with a temperature control mechanism. By adjusting the output power of the heater 8, the output temperature of the hot air can be adjusted to meet the deicing requirements in different weathers. The heater 8 is fixed in the nacelle 2, which reduces the electrostatic shielding effect of the nacelle 2, and the height of the nacelle 2 is lower than the height of the blades, which reduces the risk of lightning strike damage. The heater 8 and its temperature control mechanism are the existing basis, and are not detailed here.

The hot air output device can not only adopt the combination form of the heater 8 and the blower 7, but also can adopt the combination of the heater 8 and the induced draft fan as required. The difference is that the induced draft fan is arranged at the air outlet of the heater 8. In this case Below, the single-layer ventilation duct 9 is connected to the air outlet of the induced draft fan.

The single-layer multi-channel rotary joint 10 is arranged in the hub 4 of the wind turbine, and can rotate with the hub 4 to realize the transfer of hot air in a rotating state. The so-called multi-channel here corresponds to the number of fan blades 5 of the wind turbine; when the number of fan blades 5 is n, that is, the number of blade ventilation ducts 11 is n, the single-layer multi-channel rotary joint 10 has n+1 joints, wherein One joint is connected to the single-layer ventilation duct 9 , and the other n joints are connected to the blade ventilation ducts 11 arranged in the fan blade 5 in one-to-one correspondence. Since the number of fan blades 5 is usually three, the number of joints of the single-layer multi-channel rotary joint 10 is usually four.

In order to facilitate maintenance, the single-layer multi-channel rotary joint 10, the single-layer ventilation duct 9 and the blade ventilation duct 11 are in the form of disassembly and connection. For example, the single-layer ventilation duct 9 and the blade ventilation duct 11 can be made of heat-resistant hoses, such as Teflon tubes or nitrile rubber tubes, which are convenient to connect with the single-layer multi-channel rotary joint 10 and the air outlet of the heater 8. The assembly connection is also conducive to maintaining a certain structural stability under hot air transportation. Of course, the single-layer ventilation duct 9 and the blade ventilation duct 11 can also be metal pipes, and are assembled and connected to the heater 8 and the single-layer multi-channel rotary joint 10 through a flange structure.

When the single-layer multi-channel rotary joint 10 and the blade ventilation duct 11 are detachably connected, the blade ventilation duct 11 can also be removed to heat the interior of the hub 4. In extreme weather conditions, the heater 8 can be directly used to heat the interior of the hub 4 and the interior of the hub 4. The interior of the engine room 2 is heated to prevent the failure of the fan due to the annual high lubricating grease of the mechanical parts in the hub 4 and the engine room 2.

In order to improve the heating efficiency of the heater 8 and reduce the waste of heat in the hot air, an insulating layer, such as an insulating bag, is especially provided on the periphery of the heater 8 when the air-heat deicing device is installed. The heater 8 is isolated from the space at the rear of the engine room 2, which does not contain the rotating structure and lubricating grease, so as to reduce the loss of heat in the return air and make full use of the heat of the return air, so that the relatively low output power of the heater 8 can ensure the interior of the engine room 2. The heating temperature ensures the lubricating performance of the lubricating oil.

The setting of the blade ventilation duct 11 can be further referred to FIG. 2. In order to facilitate the hot air to be transported to the tip of the blade and then flow back into the hub 4 from the open manhole cover at the root of the blade, the end of the blade ventilation duct 11 is also provided with a backflow prevention device. The baffle 12 reduces the backflow phenomenon of the hot air in the blade. Specifically, the backflow prevention baffle 12 can be welded and fixed between the blade web 6 and the blade shell, and the backflow prevention baffle 12 can be provided with a through hole for the blade ventilation duct 11 to pass through and fix.

In another specific embodiment provided by the present invention, in order to facilitate the control of the output power of the heater 8, that is, the temperature of the hot air, the air-heat deicing device for the blades of the wind turbine is also provided with a temperature sensor. A first temperature sensor is installed in the single-layer ventilation duct 9 to detect the air temperature conveyed to the hub 4 and the blades, and a second temperature sensor is installed between the outer layer of the single-layer ventilation duct 9 and the middle passage of the generator 3 to detect the return air temperature. Temperature Sensor. The first temperature sensor and the second temperature sensor are connected to the temperature control mechanism of the heater 8; when the first temperature sensor detects that the supply air temperature is lower than the first preset value, it indicates that the supply air temperature is low and cannot meet the requirements of blade deicing The temperature control mechanism controls the heater 8 to increase the output power to increase the supply air temperature; when the second temperature sensor detects that the return air temperature is higher than the second preset value, it indicates that the supply air temperature is too high, and after deicing the blades The return air temperature is still relatively high, which not only causes energy waste, but also is not conducive to maintaining the best lubricating effect of the lubricating oil. At this time, the temperature control mechanism controls the heater 8 to reduce the output power.

The first preset value can be set to about 70°C, and the second preset value can be set to about 40°C. Of course, the first preset value and the second preset value can be based on different weather conditions in different regions and the internal lubrication of the cabin 2. The properties of the grease can be set flexibly.

In order to facilitate the control of the start of the heater 8, a third temperature sensor can also be fixed on the outer surface of the fan blade 5. The third temperature sensor is connected to the start-stop control switch of the heater 8 and the blower 7. When the third temperature sensor detects When the outside temperature is lower than the third preset value such as 0°C, the heater 8 and the blower 7 are automatically started to heat the fan blades 5 to complete deicing and defrosting. The working principles of the above-mentioned first temperature sensor, second temperature sensor, third temperature sensor, temperature control mechanism and start-up control switch can refer to the prior art. The present invention mainly realizes the automatic adjustment of the power of the heater 8 through the setting of the connection relationship. and automatic start and stop.

It should be noted that, in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such existence between these entities. The actual relationship or sequence.

The air heat deicing device for wind turbine blades provided by the present invention has been described in detail above. The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (8)

1. a wind turbine blade gas heat deicing device, is characterized in that, comprises: A hot air output device installed in the engine room (2) at the top of the wind turbine tower (1); a single-layer ventilation duct (9) connected to the air outlet of the hot air output device, the single-layer ventilation duct (9) is used to extend through the intermediate passage of the fan generator (3) to the fan hub (4); a single-layer multi-channel rotary joint (10) arranged in the fan hub (4); a blade ventilation duct (11) arranged in the inner cavity of the fan blade (5); The single-layer multi-channel rotary joint (10) is respectively connected to the single-layer ventilation duct (9) and the blade ventilation duct (11). 2. The air-heat deicing device for wind turbine blades according to claim 1, wherein the hot air output device comprises a heater (8) and a blower (7) connected to the air inlet of the heater (8). . 3 . The air-heat deicing device for wind turbine blades according to claim 2 , wherein the single-layer ventilation duct ( 9 ) is a heat-resistant hose. 4 . The air-heat deicing device for wind turbine blades according to claim 2, characterized in that the single-layer ventilation duct (9) is connected to the heater (8) and the single-layer multi-channel rotary joint (10). ) detachable connection. 5. The air-heated deicing device for wind turbine blades according to claim 2, characterized in that, the periphery of the heater (8) is provided with a space in the engine room (2) for isolating the rear of the heater (8). insulation bag. 6 . The air-heat deicing device for wind turbine blades according to claim 5 , wherein a backflow prevention baffle (12) is provided at the air outlet of the blade ventilation duct (11), and the backflow prevention baffle (12) It is used to be fixed between the blade web (6) of the fan blade (5) and the blade shell. 7. The air-heat deicing device for wind turbine blades according to any one of claims 2 to 6, wherein a first temperature sensor is provided inside the single-layer ventilation duct (9), and the single-layer ventilation duct (9) is provided with a first temperature sensor. A second temperature sensor for detecting the return air temperature is provided between the outside of the duct and the middle passage of the fan generator (3), the first temperature sensor and the second temperature sensor are connected to the heater (8) temperature control mechanism; When the first temperature sensor detects that the outlet air temperature is lower than the first preset value, the temperature control mechanism controls the heater (8) to increase the output power; when the second temperature sensor detects the return air When the temperature is higher than the second preset value, the temperature control mechanism controls the heater (8) to reduce the output power. 8 . The air-heat deicing device for wind turbine blades according to claim 7 , further comprising a third temperature sensor arranged on the outer surface of the fan blade ( 5 ), the third temperature sensor being connected to the heater (8); When the third temperature sensor detects that the temperature of the outer surface of the fan blade (5) is lower than a third preset value, the heater (8) starts heating.

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