Fan blade deicing system and method

Abstract

The present invention belongs to the field of deicing of fan blades, and specifically relates to a fan blade deicing system and method, including a fan, a heater, a three-way pipe I and a three-way pipe II, wherein pipe Ia of the three-way pipe I is connected to an air inlet of the fan, pipes Ib and Ic are respectively connected to the inside of the fan blade and the outside of a manhole baffle, pipe IIa of the three-way pipe II is connected to an air outlet of the fan, pipes IIb and IIc are respectively connected to the heater and the outside of the manhole baffle, the air outlet of the heater is located inside the fan blade, and valves are arranged on pipes Ib, Ic, IIb and IIc. The present invention can firstly deform the fan blade surface by inflation-exhaust cycle, remove most of the ice in a short time, and then perform gas-heat deicing for a relatively short time, remove the ice remaining from the deformed deicing and difficult to remove, and well combine the blade surface deformation deicing with gas-heat deicing, and has a simple and reliable structure, high efficiency, and can effectively save deicing time.

Description

Technical Field

[0001] The present invention belongs to the field of deicing of fan blades, and in particular relates to a system and method for deicing fan blades. Background Art

[0002] At present, wind turbines located in mountainous areas in the north and south are facing the problem of blades being covered with ice and unable to generate electricity in winter. After the blades are covered with ice, they usually wait for the weather to warm up and the ice to melt naturally or use de-icing methods to remove the ice. Natural ice melting will cause huge losses in power generation. Ice also has a serious impact on the safety, service life and maintenance costs of the units, causing safety hazards to surrounding people, livestock and equipment, and impacting the stable operation of the power grid, exacerbating the contradiction between electricity consumption and power generation during the icing period. De-icing methods include coating, electric heating, gas heating, hot water flushing, helicopter spraying of de-icing agents, and deformation of blade surface coating.

[0003] Air-heat deicing is a relatively mature and practical deicing method. Its principle is to use the leading edge cavity and trailing edge cavity formed by the structure of the blade itself. After the cold air is heated at the root of the blade, it is blown into the leading edge cavity by the blower, goes up along the leading edge cavity, passes through the process hole between the leading edge cavity and the trailing edge cavity of the blade tip, enters the trailing edge cavity, goes down along the trailing edge cavity, returns to the root of the blade after cooling, and is sucked in and blown by the blower again. After being heated by the heater, it is blown into the leading edge cavity again for circulation. The disadvantage of this deicing method is that it takes a long time to deicing. Most of the ice on the surface of the blade is removed, especially the ice on the windward side of the leading edge of the blade is removed, and it takes 2 hours to meet the start-up conditions; secondly, the deicing consumes a lot of electricity. A 2MW wind turbine requires a heating system of hundreds of kilowatts. Each deicing operation time is also very long, resulting in high self-consumption of electricity; thirdly, the deicing heat is unevenly distributed, the leading edge cavity has more heat, the trailing edge cavity has less heat, the blade tip area is small, the surface is thin, and the ice is removed first, followed by the leading edge cavity surface, and finally the trailing edge cavity surface.

[0004] The method of deicing by deformation of the film on the blade surface is to add a layer of film on the blade surface. After the blade surface is frozen, the film on the outer surface of the blade is repeatedly expanded and dented by repeatedly inflating and exhausting the inner cavity between the film and the blade, so as to separate from the ice and remove the ice. This method has a fast deicing speed and low self-power consumption. At the same time, the production process is very complicated, the cost is high, and the service life is short, which is not conducive to promotion and use. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a fan blade deicing system and method which combines air heat and fan blade surface deformation deicing methods.

[0006] The content of the present invention includes a fan, a heater, a three-way pipe I and a three-way pipe II. The pipe Ia of the three-way pipe I is connected to the air inlet of the fan, and the pipes Ib and Ic are respectively connected to the inside of the fan blades and the outside of the manhole baffle. The pipe IIa of the three-way pipe II is connected to the air outlet of the fan, and the pipes IIb and IIc are respectively connected to the heater and the outside of the manhole baffle. The air outlet of the heater is located inside the fan blades. The pipes Ib, Ic, IIb and IIc are all provided with valves, and also include a controller electrically connected to the fan, the heater and each valve.

[0007] Furthermore, the fan, heater, three-way pipe I and three-way pipe II are all arranged inside the fan blades.

[0008] Furthermore, the pipe Ic and the pipe IIc are connected to each other and penetrate the manhole baffle through a pipeline.

[0009] Furthermore, the fan is a blower.

[0010] Furthermore, a pressure relief valve is provided on the manhole baffle, and the pressure relief valve is electrically connected to the controller.

[0011] Furthermore, a pressure gauge is provided on the manhole baffle, and the pressure gauge is electrically connected to the controller.

[0012] Furthermore, the tube Ia is a Venturi tube.

[0013] Furthermore, the heater includes a connecting pipe, a heating chamber and an output pipe which are arranged in sequence, the connecting pipe is connected to the pipe IIa, and the output pipe is extended to the tip of the fan blade.

[0014] The present invention also provides a fan blade deicing method, including a fan blade deicing system, comprising the following steps:

[0015] S1, real-time monitoring of the ice coverage of the fan blades, and corresponding deformation deicing, gas-heat deicing or combined deicing according to the ice coverage; in case of deformation deicing, go to step S2 or S3; in case of gas-heat deicing, go to step S5; combined deicing is first deformation deicing and then gas-heat deicing;

[0016] S2, the controller controls the valves on pipe IIb and pipe Ic to open, and other valves to close, and turns on the fan to inflate the fan blades. When the inflation pressure reaches the set value, the fan is turned off, and the process goes to step S3;

[0017] S3, the controller controls the valves on pipe IIc and pipe Ib to open, and other valves to close, and turns on the fan to exhaust air from the fan blades. When the exhaust pressure reaches the set value, the fan is turned off, and the process goes to step S4;

[0018] S4, repeating S2-S3 once or multiple times according to a set time or a set number of repetitions, or according to the ice coverage of the fan blades; and entering step S1;

[0019] S5, the controller controls the valves on pipe Ib and pipe IIb to open, and other valves to close, and turns on the fan and heater to heat and de-ice the fan blades. The fan and heater are turned off according to the set time or according to the ice coverage of the fan blades, and enters step S1.

[0020] Furthermore, it includes a pressure gauge and a pressure relief valve. During steps S2 and S3, the pressure gauge monitors the pressure inside the fan blades. When the abnormal pressure inside the fan blades reaches the maximum safe pressure or the minimum safe pressure, the pressure signal is fed back to the controller, and the controller controls the pressure relief valve to open, so that the internal pressure of the fan blades is balanced with the set value.

[0021] The beneficial effect of the present invention is that the present invention connects three-way pipe I and three-way pipe II to the air inlet and the air outlet of the fan respectively, and connects the other two pipes of three-way pipe I and three-way pipe II to the inside and outside of the fan blade respectively, and arranges them inside the fan blade, and one of the pipes passes through a heater, and in combination with the setting of a valve, it can realize deformation deicing on the surface of the fan blade, gas-heat deicing inside, or combined deicing. Specifically, it can realize that the surface of the fan blade is first deformed by a bulging-sunken cycle through an inflation-exhaust cycle, most of the ice is removed in a short time, and then gas-heat deicing is performed for a shorter time. , remove the remaining ice that is difficult to remove after deformation deicing, and well combine blade surface deformation deicing with gas-heat deicing, that is, fast deformation large-area deicing and gas-heat local stubborn deicing, solve the problem of slow deicing speed caused by gas-heat deicing due to heating inside the blade and heat passing through the blade material to the blade surface for deicing, and enhance the deicing effect as a whole. The structure is simple and reliable. Compared with traditional gas-heat deicing, only a few pipelines and valves are added. At the same time, deformation deicing has fast speed and high efficiency, which can effectively save deicing time. The time required is less than that of single gas-heat deicing. In addition, blade deformation deicing only requires a small amount of self-consumption electricity to remove most of the ice, and gas-heat deicing requires little self-consumption electricity to remove the remaining ice. The total power consumption of the two items is much less than that of single gas-heat deicing, thereby reducing self-consumption electricity.

[0022] In addition, compared with the current method of coating the surface of fan blades and inflating and deflating the coating for deicing, the present application has a simpler structure and lower cost. The method of coating the surface and inflating and deflating the coating for deicing can only be installed when the fan blades are produced, and has extremely high process requirements and high costs. It is also difficult to combine with the gas-heat deicing method. The present application utilizes the structural deformation of the fan blades themselves for deicing, which has extremely low cost and can be achieved by modifying existing fans and adding new fans. At the same time, it makes good use of the material properties and structural properties of the fan blades. Specifically, fan blades are generally made of fiberglass, which has the characteristics of good flexibility and strong deformation resistance. The structure is generally a hollow structure with a thin outer wall, which is easy to deform and reset by inflation and exhaust. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the installation schematic diagram of the present invention.

[0024] Figure 2 It is a schematic diagram of the structure of the present invention.

[0025] In the figure, 1-pressure gauge; 2-pressure relief valve; 3-safety valve; 4-tee pipe I; 401-tube Ia; 402-tube Ib; 403-tube Ic; 5-tee pipe II; 501-tube IIa; 502-tube IIb; 503-tube IIc; 6-tee pipe III; 7-fan; 8-heater; 801-connecting pipe; 802-heating chamber; 803-output pipe; 9-fan blades; 10-manhole baffle; 11-valve. DETAILED DESCRIPTION

[0026] like Figure 1-2 As shown, the present invention includes a fan 7, a heater 8, a three-way pipe I4 and a three-way pipe II5, wherein the pipe Ia401 of the three-way pipe I4 is connected to the air inlet of the fan 7, the pipe Ib402 and the pipe Ic403 are respectively connected to the inside of the fan blade 9 and the outside of the manhole baffle 10, the pipe IIa501 of the three-way pipe II5 is connected to the air outlet of the fan 7, the pipe IIb502 and the pipe IIc503 are respectively connected to the heater 8 and the outside of the manhole baffle 10, the air outlet of the heater 8 is located inside the fan blade 9, the pipe Ib402, the pipe Ic403, the pipe IIb502 and the pipe IIc503 are all provided with valves 11, and also include a controller electrically connected to the fan 7, the heater 8 and each valve 11.

[0027] The present invention connects the three-way pipe I4 and the three-way pipe II5 to the air inlet and the air outlet of the fan 7 respectively, and connects the other two pipes of the three-way pipe I4 and the three-way pipe II5 to the inside and the outside of the fan blade 9 respectively, and sets one of the pipes inside the fan blade 9 through the heater 8, and cooperates with the setting of the valve 11 to realize the deformation deicing of the surface of the fan blade 9, the internal gas-heat deicing or the combined deicing. Specifically, it can realize the inflation-exhaust cycle to make the surface of the fan blade 9 bulge-sag cycle deformation, remove most of the ice in a short time, and then perform gas-heat deicing for a shorter time. Ice, and remove the remaining ice that is difficult to remove after deformation deicing, so as to combine the deformation deicing of the blade surface with gas-heat deicing, realize the combination of deformation fast large-area deicing and gas-heat local stubborn deicing, solve the problem of slow deicing speed caused by gas-heat deicing due to heating inside the blade, and the heat is transferred to the blade surface through the blade material for deicing, and the deicing effect is enhanced as a whole, and the structure is simple and reliable. Compared with traditional gas-heat deicing, only a few pipelines and valves are added. At the same time, the deformation deicing speed is fast and efficient, which can effectively save deicing time, and the time required is less than that of single gas-heat deicing. In addition, blade deformation deicing only requires a small amount of self-consumption electricity to remove most of the ice, and gas-heat deicing requires little self-consumption electricity to remove the remaining ice. The total power consumption of the two combined is much less than that of single gas-heat deicing, thereby reducing self-consumption electricity.

[0028] In addition, compared with the current method of coating the surface of fan blades and inflating and deflating the coating for deicing, the present application has a simpler structure and lower cost. The method of coating the surface and inflating and deflating the coating for deicing can only be installed when the fan blades are produced, and has extremely high process requirements and high costs. It is also difficult to combine with the gas-heat deicing method. The present application utilizes the structural deformation of the fan blades 9 themselves to de-ice, which has extremely low cost and can be achieved by modifying existing fans and adding new fans. At the same time, it makes good use of the material properties and structural properties of the fan blades to achieve deformation deicing. Specifically, fan blades are generally made of fiberglass, which has the characteristics of good flexibility and strong deformation resistance. The structure is generally a hollow structure with a thin outer wall, which is easy to deform and reset by inflation and exhaust.

[0029] The fan 7, heater 8, three-way pipe I4 and three-way pipe II5 are all arranged inside the fan blade 9, preferably at the root of the fan blade 9, close to the manhole baffle 10, which is convenient for installation and maintenance, while reducing the influence of the deicing structure on the rotation of the fan blade 9. In addition, if they are not arranged in the fan hub, they do not occupy the space of the hub.

[0030] The pipe Ic403 and the pipe IIc503 are interconnected to form a three-way pipe III6, which can penetrate the manhole baffle 10 and connect to the outside of the fan blade 9 through only one pipe, reduce the number and area of ​​perforations in the manhole baffle 10, and reduce installation and sealing costs.

[0031] The fan 7 is a blower, which has a simple and reliable structure and low cost.

[0032] A pressure relief valve 2 is provided on the manhole baffle 10, and the pressure relief valve 2 is electrically connected to the controller. The safety of the fan blades is ensured by setting the pressure relief valve 2 to avoid excessive deformation of the fan blades 9. In addition, a safety valve 3 can also be provided. The safety valve 3 adopts mechanical pressure relief and the pressure can be set. When the pressure reaches the set value, the pressure can be automatically released to ensure the safety of the fan blades when the control circuit fails and the pressure relief valve 2 fails to work.

[0033] The manhole baffle 10 is provided with a pressure gauge 1 , which is electrically connected to the controller. By providing the pressure gauge 1 , the pressure value in the fan blade 9 can be monitored in real time.

[0034] The tube Ⅰa401 is a Venturi tube, which is convenient for measuring and monitoring fluid pressure difference.

[0035] The heater 8 includes a connecting pipe 801, a heating chamber 802 and an output pipe 803 which are arranged in sequence. The connecting pipe 801 is connected to the pipe IIa501. The output pipe 803 is extended to the tip of the fan blade 9. The heating chamber 802 can heat the gas flowing through by the heating element, thereby heating the inner surface of the fan blade 9. By extending the output pipe 803 to the tip of the fan blade 9, the tip and the belly of the blade are de-iced. Since it is difficult to remove ice from the tip and the belly of the blade due to blade deformation, gas-heat deicing can make up for the above-mentioned shortcomings. Gas-heat deicing has a poor deicing effect on the blade trailing edge cavity, and deicing due to blade surface deformation makes up for its shortcomings, resulting in a better deicing effect.

[0036] The present invention also provides a fan blade deicing method, including a fan blade deicing system, comprising the following steps:

[0037] S1, real-time monitoring of the ice coverage of the fan blades 9, and corresponding deformation deicing, gas-heat deicing or combined deicing according to the ice coverage; when the deformation deicing is performed, step S2 or S3 is entered, and it can be selected whether to inflate or exhaust first according to the situation; when the gas-heat deicing is performed, step S5 is entered; combined deicing is first deformation deicing and then gas-heat deicing;

[0038] S2, the controller controls the valves 11 on the pipe IIb502 and the pipe Ic403 to open, and the other valves 11 to close, and the fan 7 is turned on to inflate the fan blades 9, and the fan 7 is turned off after the inflation pressure reaches the set value, and the process goes to step S3;

[0039] S3, the controller controls the valves 11 on the pipe IIc503 and the pipe Ib402 to open, and the other valves 11 to close, and the fan 7 is turned on to exhaust the inside of the fan blades 9. After the exhaust pressure reaches the set value, the fan 7 is turned off, and the process goes to step S4;

[0040] S4, repeat S2-S3 once or multiple times according to the set time or the set number of repetitions, or according to the ice coverage of the fan blades 9; and proceed to step S1;

[0041] S5, the controller controls the valves 11 on the tube Ⅰb402 and the tube Ⅱb502 to open, and the other valves 11 to close, and turns on the fan 7 and the heater 8 to heat and de-ice the fan blades 9, and turns off the fan 7 and the heater 8 according to the set time or according to the ice coverage of the fan blades 9, and enters step S1.

[0042] After the deformation deicing, it is determined that the step S1 is required to assist with gas-heat deicing, that is, a combination of deformation deicing and gas-heat deicing is achieved.

[0043] It also includes a pressure gauge 1 and a pressure relief valve 2. During steps S2 and S3, the pressure gauge 1 monitors the pressure inside the fan blade 9. When an abnormal pressure inside the fan blade 9 reaches the maximum safe pressure or the minimum safe pressure, the pressure signal is fed back to the controller, and the controller controls the pressure relief valve 2 to open, so that the internal pressure of the fan blade 9 is balanced with the set value.

[0044] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0045] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A method for deicing fan blades, characterized in that: The invention comprises a fan blade deicing system, wherein the fan blade deicing system comprises a fan (7), a heater (8), a three-way pipe I (4) and a three-way pipe II (5), wherein the pipe Ia (401) of the three-way pipe I (4) is connected to the air inlet of the fan (7), the pipe Ib (402) and the pipe Ic (403) are respectively connected to the inside of the fan blade (9) and the outside of the manhole baffle (10), and the pipe IIa (501) of the three-way pipe II (5) is connected to the fan (7) The pipe IIb (502) and the pipe IIc (503) are connected to the heater (8) and the outside of the manhole baffle (10) respectively, the air outlet of the heater (8) is located inside the fan blade (9), the pipe Ib (402), the pipe Ic (403), the pipe IIb (502) and the pipe IIc (503) are all provided with valves (11), and also include a controller electrically connected to the fan (7), the heater (8) and each valve (11); The fan blade deicing method comprises the following steps: S1, real-time monitoring of the ice coverage of the fan blades (9), and performing deformation deicing, gas-heat deicing or combined deicing according to the ice coverage; in the case of deformation deicing, step S2 or S3 is entered; in the case of gas-heat deicing, step S5 is entered; combined deicing is first deformation deicing and then gas-heat deicing; S2, the controller controls the valves (11) on the pipe IIb (502) and the pipe Ic (403) to open, and the other valves (11) to close, and the fan (7) to inflate the fan blades (9), and when the inflation pressure reaches the set value, the fan (7) is turned off, and the process goes to step S3; S3, the controller controls the valves (11) on the pipe IIc (503) and the pipe Ib (402) to open, and the other valves (11) to close, and the fan (7) is turned on to exhaust the inside of the fan blades (9). After the exhaust pressure reaches the set value, the fan (7) is turned off, and the process goes to step S4; S4, repeating S2-S3 once or multiple times according to a set time or a set number of repetitions, or according to the ice coverage of the fan blades (9); and entering step S1; S5, the controller controls the valves (11) on the pipe Ib (402) and the pipe IIb (502) to open, and the other valves (11) to close, and turns on the fan (7) and the heater (8) to heat and de-ice the fan blades (9), and turns off the fan (7) and the heater (8) according to the set time or according to the ice coating on the fan blades (9), and enters step S1.

2. The fan blade deicing method according to claim 1, characterized in that: The invention comprises a pressure gauge (1) and a pressure relief valve (2). During the process of steps S2 and S3, the pressure gauge (1) monitors the pressure inside the fan blade (9). When an abnormal pressure inside the fan blade (9) reaches the maximum safe bearing pressure or the minimum safe bearing pressure, a pressure signal is fed back to a controller, and the controller controls the pressure relief valve (2) to open, so that the internal pressure of the fan blade (9) is balanced with the set value.

3. The fan blade deicing method according to claim 1, characterized in that: The fan (7), heater (8), three-way pipe I (4) and three-way pipe II (5) are all arranged inside the fan blade (9).

4. The fan blade deicing method according to claim 1, characterized in that: The pipe Ic (403) and the pipe IIc (503) are connected to each other and penetrate the manhole baffle (10) through a pipeline.

5. The fan blade deicing method according to claim 1, characterized in that: The fan (7) is a blower.

6. The fan blade deicing method according to claim 1, characterized in that: A pressure relief valve (2) is provided on the manhole baffle (10), and the pressure relief valve (2) is electrically connected to a controller.

7. The fan blade deicing method according to claim 6, characterized in that: A pressure gauge (1) is provided on the manhole baffle (10), and the pressure gauge (1) is electrically connected to the controller.

8. The fan blade deicing method according to claim 1, characterized in that: The tube Ⅰa (401) is a Venturi tube.

9. The fan blade deicing method according to claim 1, characterized in that: The heater (8) comprises a connecting pipe (801), a heating chamber (802) and an output pipe (803) which are arranged in sequence, and the connecting pipe (801) is connected to the pipe IIa (501).

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