阅读说明：本技术 一种风机叶片除冰系统及其工作方法 (Fan blade deicing system and working method thereof ) 是由 许扬 蔡安民 林伟荣 焦冲 于 2021-02-26 设计创作，主要内容包括：本发明公开的一种风机叶片除冰系统及其工作方法,属于风力发电技术领域。包括风机出口管道、第一气路、第二气路和挡板；风机出口管道为直管,第一气路和第二气路在叶片前缘和腹板之间分层迂回排列,第一气路靠近叶片前缘设置；挡板分别于叶片前缘和腹板固定连接,挡板上开设有贯通的第一气路接口和第二气路接口；第一气路的一端与风机出口管道连接,另一端与第一气路接口连接；第二气路的一端与风机出口管道连接,另一端与第二气路接口连接；第二气路上设有阀门,叶片前缘上设有叶片前缘测温仪,腹板上设有腹板测温仪。本发明优化了风机叶片内除冰管道的结构,改善了叶片内部的传热效果,提高了除冰系统的经济性和安全性。(The invention discloses a fan blade deicing system and a working method thereof, and belongs to the technical field of wind power generation. The air conditioner comprises a fan outlet pipeline, a first air path, a second air path and a baffle plate; the fan outlet pipeline is a straight pipe, the first air path and the second air path are arranged between the front edge of the blade and the web plate in a layered and circuitous manner, and the first air path is arranged close to the front edge of the blade; the baffle is fixedly connected with the front edge of the blade and the web respectively, and a first air path interface and a second air path interface which are communicated are arranged on the baffle; one end of the first air path is connected with the outlet pipeline of the fan, and the other end of the first air path is connected with the first air path interface; one end of the second air path is connected with the outlet pipeline of the fan, and the other end of the second air path is connected with the second air path interface; and a valve is arranged on the second gas path, a blade leading edge temperature measuring instrument is arranged on the blade leading edge, and a web temperature measuring instrument is arranged on the web. The invention optimizes the structure of the deicing pipeline in the fan blade, improves the heat transfer effect in the blade and improves the economy and the safety of a deicing system.)

1. A fan blade deicing system is characterized by comprising a fan outlet pipeline (1), a first air path (4), a second air path (3) and a baffle (7); the fan outlet pipeline (1) is a straight pipe, the first air path (4) and the second air path (3) are arranged between the blade front edge (5) and the web (9) in a layered and circuitous manner, and the first air path (4) is arranged close to the blade front edge (5); the baffle (7) is fixedly connected with the blade front edge (5) and the web (9) respectively, and the baffle (7) is provided with a first air path interface (702) and a second air path interface (701) which are communicated; one end of the first air path (4) is connected with the fan outlet pipeline (1), and the other end of the first air path is connected with the first air path interface (702); one end of the second air path (3) is connected with the fan outlet pipeline (1), and the other end of the second air path is connected with the second air path connector (701); the second air passage (3) is provided with a valve (2), the blade front edge (5) is provided with a blade front edge temperature measuring instrument (6), and the web (9) is provided with a web temperature measuring instrument (8).

2. Fan blade de-icing system according to claim 1, wherein the first air channel (4) and the second air channel (3) are located at the trisections between the blade leading edge (5) and the web (9), respectively.

3. Fan blade de-icing system according to claim 1, characterized in that the first air path (4) and the second air path (3) are square wave shaped.

4. Fan blade deicing system according to claim 3, characterized in that the section of the first air path (4) near the leading edge (5) of the blade matches the curvature of the leading edge (5) of the blade.

5. Fan blade de-icing system according to claim 1, wherein the distribution density of the first gas circuit (4) and the second gas circuit (3) increases along the fan outlet duct (1) to the baffle (7).

6. Fan blade de-icing system according to claim 1, characterised in that the first air duct (4) and the second air duct (3) have a circuitous amplitude greater than 30 cm.

7. Fan blade de-icing system according to claim 1, wherein the first air path (4) and the second air path (3) have a reverse winding direction.

8. Fan blade deicing system according to claim 1, characterized in that the fan outlet duct (1) has a length of 2-3 m.

9. The method for operating a fan blade deicing system according to any one of claims 1 to 8, comprising:

when the fan blade needs to be heated, deicing air flows through the air heater to enter the fan outlet pipeline (1), when the difference between the temperature measured by the blade leading edge thermodetector (6) and the temperature measured by the web thermodetector (8) is smaller than a preset temperature difference value, the valve (2) is closed, and the deicing air flows only in the first air passage (4) for heat exchange; when the difference between the temperature measured by the blade leading edge thermodetector (6) and the temperature measured by the web thermodetector (8) is larger than or equal to a preset temperature difference value, the valve (2) is opened, the deicing air flow is divided into two parts which respectively flow through a first air path (4) and a second air path (3), and then are mixed through a first air path interface (702) and a second air path interface (701) on the baffle, and flow towards the blade tip, and then bypass the end part of the web (9) after reaching the blade tip, enter a space surrounded by the web (9) and the blade trailing edge (10) for heat exchange, and then flow out of the blade at the blade root (11).

10. Method of operating a fan blade de-icing system according to claim 9, characterised in that the preset temperature difference value is 5 ℃.

Technical Field

The invention belongs to the technical field of wind power generation, and particularly relates to a fan blade deicing system and a working method thereof.

Background

With the continuous development of wind power generation, a plurality of wind power plants are located in areas easy to freeze, and when the ambient temperature is reduced to about 0 ℃, the phenomenon of icing is easy to occur. Once the blade surface is frozen, it causes problems of performance degradation, mechanical failure, etc., and causes additional economic loss due to frozen shutdown. Currently, the research on the deicing technology of the wind generating set can be roughly divided into two categories: firstly, a hot blast deicing technology; and the other is an electric heating deicing technology. The hot blast deicing method has the characteristics of controllable technical risk, convenience in installation, no lightning risk, suitability for new installation and modification and the like, so that the method is widely adopted.

The existing hot blast deicing technology utilizes a heat conduction pipe to send hot air into the interior of a fan blade to exchange heat with the blade. In actual operation, the blade tip dissipates heat faster due to the higher linear speed, so the icing trend is more obvious. However, when heat exchange is performed with hot air, the closer to the blade tip, the lower the temperature of the air flow is, and the smaller the flow passage is, the shorter the residence time of the air flow is, which is extremely undesirable for the heat transfer effect. If the heating is seriously uneven, the thermal stress in the blade is overlarge, the fatigue and the aging of the blade are accelerated, and the adverse effect is brought to the safety of a machine set.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a fan blade deicing system and a working method thereof, which optimize the structure of a deicing pipeline in a fan blade, improve the heat transfer effect inside the blade, and improve the economy and safety of the deicing system.

The invention is realized by the following technical scheme:

the invention discloses a fan blade deicing system which comprises a fan outlet pipeline, a first air path, a second air path and a baffle plate, wherein the first air path is communicated with the fan outlet pipeline; the fan outlet pipeline is a straight pipe, the first air path and the second air path are arranged between the front edge of the blade and the web plate in a layered and circuitous manner, and the first air path is arranged close to the front edge of the blade; the baffle is fixedly connected with the front edge of the blade and the web respectively, and a first air path interface and a second air path interface which are communicated are arranged on the baffle; one end of the first air path is connected with the outlet pipeline of the fan, and the other end of the first air path is connected with the first air path interface; one end of the second air path is connected with the outlet pipeline of the fan, and the other end of the second air path is connected with the second air path interface; and a valve is arranged on the second gas path, a blade leading edge temperature measuring instrument is arranged on the blade leading edge, and a web temperature measuring instrument is arranged on the web.

Preferably, the first air passage and the second air passage are respectively located at trisections between the leading edge of the blade and the web.

Preferably, the first air path and the second air path are square wave shaped.

Further preferably, the duct section of the first air path near the leading edge of the blade is matched to the curvature of the leading edge of the blade.

Preferably, the distribution density of the first gas path and the second gas path increases along the fan outlet duct to the baffle.

Preferably, the circuitous amplitudes of the first air path and the second air path are more than 30 cm.

Preferably, the first air passage and the second air passage have opposite winding directions.

Preferably, the length of the fan outlet pipeline is 2-3 m.

The working method of the fan blade deicing system disclosed by the invention comprises the following steps:

when the fan blade needs to be heated, deicing air flows through the air heater to enter the fan outlet pipeline, when the difference between the temperature measured by the blade leading edge temperature measuring instrument and the temperature measured by the web temperature measuring instrument is smaller than a preset temperature difference value, the valve is closed, and the deicing air only flows in the first air path to exchange heat; when the difference between the temperature measured by the blade leading edge thermodetector and the temperature measured by the web thermodetector is larger than or equal to a preset temperature difference value, the valve is opened, the deicing airflow is divided into two paths which respectively flow through the first air path and the second air path, then the two paths are mixed through the first air path interface and the second air path interface on the baffle, and then the deicing airflow flows to the blade tip, bypasses the end part of the web after reaching the blade tip, enters a space surrounded by the web and the trailing edge of the blade for heat exchange, and then flows out of the blade at the blade root.

Preferably, the preset temperature difference value is 5 ℃.

Compared with the prior art, the invention has the following beneficial technical effects:

in the existing technical scheme, a downstream heat transfer arrangement mode is adopted for fan hot blast deicing no matter a heat conduction pipe is used or a flow channel is formed by a web plate of a blade, the temperature of heat exchange airflow at the tip end of the blade is low, the flow speed is high, the retention time of the deicing airflow is short, and the heat transfer effect is reduced, which is not in accordance with the actual situation that icing is serious near the tip part. Meanwhile, the deicing pipeline is arranged close to the front edge of the blade, and uneven heating to a certain degree can be caused in the chord length direction.

The fan blade deicing system disclosed by the invention optimizes the design of a fan blade deicing pipeline, and reasonably controls the retention time of gas through the design of a flow channel along the spanwise direction of the blades, so that the heat distribution and the icing interval have higher conformity. Two layers of gas circuits are arranged in the direction along the chord length, so that the interior of the blade is uniformly heated, and the thermal stress is reduced. The air flow from the outlet of the hot air blower is sent into a first air path which is arranged close to the front edge of the blade. The fan outlet pipeline adopts a straight pipe, after the straight pipe enters one section of the blade and reaches the first air path and the second air path, the straight pipe is arranged by adopting a circuitous air path, the retention time of air flow in unit span distance is increased, the heat exchange time is increased along with the straight pipe, the heat exchange effect is enhanced, and the straight pipe has a better effect on removing the ice coating close to the blade tip. And closed-loop adjustment is performed through real-time temperature feedback of the blade leading edge temperature measuring instrument and the web temperature measuring instrument, and the opening of the valve on the second air passage is adjusted, so that the internal temperature of the blade is balanced, and the generation of large thermal stress in the chord length direction is avoided. The invention optimizes the structure of the deicing pipeline in the fan blade, improves the heat transfer effect in the blade and improves the economy and the safety of a deicing system.

Furthermore, the first air path and the second air path are uniformly distributed between the front edge of the blade and the web, so that the temperature unevenness along the chord length direction of the blade can be avoided.

Furthermore, the first air path and the second air path are square wave-shaped, and the processing and the installation can be facilitated.

Furthermore, the pipe section of the first air path close to the front edge of the blade is matched with the curvature of the front edge of the blade, so that the heating effect on the front edge of the blade can be improved.

Furthermore, the distribution density of the first air path and the second air path is increased from the outlet pipeline of the fan to the baffle, the longer the retention time of the unit spanwise airflow is, the longer the heat exchange time is, the stronger the heat exchange effect is, and the removal effect of the ice coating at the part close to the blade tip can be improved.

Furthermore, the circuitous amplitude of the first air path and the second air path is larger than 30cm, and the local loss of the air flow can be reduced.

Furthermore, the first air path and the second air path are opposite in circuitous direction, so that heat flow can be better distributed, and uneven temperature inside the blade is reduced.

According to the working method of the fan blade deicing system, disclosed by the invention, the heat transfer effect inside the blade can be improved and the balance of the temperature inside the blade is improved through the real-time temperature feedback of the blade leading edge temperature measuring instrument and the web temperature measuring instrument, so that the fan blade deicing system has a good application prospect.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a view A-A of FIG. 1;

FIG. 3 is a view B-B of FIG. 1;

fig. 4 is a schematic structural view of the baffle.

In the figure: 1-a fan outlet duct; 2-a valve; 3-a second gas path; 4-a first gas path; 5-the leading edge of the blade; 6-blade leading edge thermodetector; 7-a baffle plate; 701-a second gas path interface; 702-a first gas path interface; 8-web thermometric indicator; 9-a web; 10-the trailing edge of the blade; 11-a blade root; 12-a suction surface; 13-pressure side.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings, which are included to illustrate and not to limit the invention:

referring to fig. 1, the fan blade deicing system of the present invention includes a fan outlet pipe 1, a first air path 4, a second air path 3, and a baffle 7. Fan export pipeline 1 is the straight tube, and fan export pipeline 1's length is 2 ~ 3m generally.

The first air path 4 and the second air path 3 are arranged between the blade leading edge 5 and the web 9 in a layered and circuitous way, and the first air path 4 is arranged close to the blade leading edge 5; preferably, the first air passage 4 and the second air passage 3 are located at trisections between the blade leading edge 5 and the web 9, respectively.

As shown in fig. 4, the baffle 7 is fixedly connected to the blade leading edge 5 and the web 9, and the baffle 7 is provided with a first air passage interface 702 and a second air passage interface 701 which are through; one end of the first air passage 4 is connected with the fan outlet pipeline 1, and the other end is connected with the first air passage interface 702; one end of the second air path 3 is connected with the fan outlet pipeline 1, and the other end is connected with the second air path connector 701.

The second gas path 3 is provided with a valve 2, the blade front edge 5 is provided with a blade front edge temperature measuring instrument 6, and the web 9 is provided with a web temperature measuring instrument 8.

Referring to fig. 2 and 3, in a preferred embodiment of the present invention, the first air path 4 and the second air path 3 are in a square waveform, the section of the first air path 4 close to the leading edge 5 of the vane matches the curvature of the leading edge 5 of the vane, and meanwhile, the distribution density of the first air path 4 and the second air path 3 increases along the outlet pipeline 1 of the fan to the baffle 7. The circuitous amplitude of the first air path 4 and the second air path 3 is larger than 30cm, and the circuitous direction of the first air path 4 and the second air path 3 is opposite. The first air passage 4 and the second air passage 3 may also adopt a sinusoidal waveform.

The working principle of the invention is as follows:

the deicing air flow is heated by the heater at a position close to the blade root 11 and enters the blade inner duct from the fan outlet duct 1. The initial segment air current flows along hugging closely the pipeline of blade leading edge 5, and in the position 2 ~ 3 meters apart from the fan export, through arranging of three-way valve, deicing air current pipeline divide into first gas circuit 4 and second gas circuit 3, and the flow between two gas circuits is adjusted through valve 2. For the first air path 4 it is arranged along a position next to the leading edge 5 of the blade. In order to adjust the residence time of the air flow, the first air path 4 adopts a curved air path arrangement, and the embodiment adopts a square wave-shaped curved loop. The smooth joints are adopted for connecting the pipelines, so that the local resistance of gas flow is reduced. At different positions along the span, the pitch of the square-wave waveform is reduced, i.e.The closer to the direction of the blade tips, the more densely the square wave-shaped bent pipelines are distributed, the longer the retention time of the airflow in the unit spanwise direction is, the longer the heat exchange time is, and the heat exchange effect is enhanced. For the second gas path 3 arranged close to the web 9, the aim is to reduce the temperature unevenness along the chord direction of the blade. The second air channel 3 is arranged between the web 9 and the blade leading edge 5, and is spaced from the blade leading edge 5 by two thirds of the distance between the blade leading edge 5 and the web 9, namely, the distance between the blade leading edge 5 and the web 9 is one third of the distance between the blade leading edge 5 and the web 9. And the second gas circuit 3 is provided with a gas flow regulating valve 2, and the gas flow of the second gas circuit 3 is reasonably regulated according to the temperature distribution of the blades. A blade leading edge temperature measuring instrument 6 is arranged at the middle section of the blade leading edge 5, and a web temperature measuring instrument 8 is arranged at the position corresponding to the web 9. When the deicing system is just started to work, the valve 2 is in a closed state, and the deicing air flow only flows through the first air passage 4 to exchange heat. Reading the temperature T of the vane leading edge thermodetector 6₀And the temperature T of the web thermometer 8₁When T is₁Ratio T₀When the temperature is lower by more than 5 ℃, the opening degree of the valve 2 is gradually increased until T₁And T₀The temperature difference between them is within 5 ℃, namely T₀And T₁And closed-loop control of the opening degree of the valve 2 is realized. The tail ends of the first air path 4 and the second air path 3 are connected to the baffle 7 and are tightly bonded. After flowing through the baffle, the airflows of the first air path 4 and the second air path 3 are mixed in the internal channel of the blade and flow to the blade tip. The baffle 7 is sealed with the inner surface of the blade and the web plate to prevent air flow from flowing back. The deicing airflow flows to the blade tip, flows around the web 9, enters a space surrounded by the web 9 and the blade trailing edge 10 for heat exchange, and then flows out of the blade at the blade root 11.

Fig. 2 is a schematic view of the second gas circuit 3 viewed from the direction a-a, the circuit being arranged between the pressure surface 12 and the suction surface 13. The closer to the blade root 11, the more densely the square wave-shaped curved pipelines are distributed. In order to reduce the local loss of the air flow, the shortest square wave pipeline is not shorter than 30 cm.

Fig. 3 is a schematic view of the first air passage 4 viewed from the direction B-B. The line is arranged between the pressure surface 12 and the suction surface 13. The closer to the blade root 11, the more densely the square wave-shaped curved pipelines are distributed. The arrangement mode of the square wave pipeline of the second air path 3 is staggered with that of the first air path 4, so that the heat is distributed more uniformly in space, and the thermal stress is reduced.

FIG. 4 is a schematic cross-sectional view of a baffle. The second air path 3 is connected with and closely adhered to the second air path interface 701 on the baffle 7, and the first air path 4 is connected with and closely adhered to the first air path interface 702 on the baffle 7.

The above description is only a part of the embodiments of the present invention, and although some terms are used in the present invention, the possibility of using other terms is not excluded. These terms are used merely for convenience in describing and explaining the nature of the invention and are to be construed as any additional limitation which is not in accordance with the spirit of the invention. The foregoing is merely an illustration of the present invention for the purpose of providing an easy understanding and is not intended to limit the present invention to the particular embodiments disclosed herein, and any technical extensions or innovations made herein are protected by the present invention.