This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

風力發電機製作及

相關物理計算MAKING OF WIND TURBINEAND RELATED CALCULATION

香港理工大學應用物理學系學生

翟振亨HKPU

Applied Physics StudentChka Chun Hang

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

目錄

引言理論發電機的設計製作過程相關計算演示

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Where do winds come from?風從哪裡來 ?

Because of the temperature differences(溫差 ) around the world

Surface Wind

Convection updraft of rising warm Air

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

What is wind turbine(風力發電機 )?

Wind’s kinetic energy(動能 )

-> electrical energy( 電能 )

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Theory理論

By Lenz’s Law (冷次定律 ) Induced current(感生電流 ) opposes ( 對抗 ) the change of the magnetic force

Heinrich Lenz 海因里希 ·冷次

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Theory理論

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Theory理論

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Induced emf-感生電壓

Where ,N is the number of turn of coil,B is the magnetic field strength

( 磁場強度 )A is the area(面積 ) of the coil

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Brace 支架

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Axle 軸

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Turbine 渦輪

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Rotor 轉片

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Coil 電線圈

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Supporting Base支撐底部

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Design-設計 (3D View)

Magnet 磁鐵

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Material-物料

Screw(螺絲 ) x 8 Bearing(滾珠軸承 )x 2Wooden borad(5”x10”) Wooden board(2”x10”)

Copper wire(漆皮銅線 ) Chopstick(筷子 ) x 3Water bottle(水樽 ) Magnet (磁石 )x

4LED 燈 x 1 CD case x 1

)

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

1. Preparing the material

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

2.making the frame(骨架 ) and base

1 2 3

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

Finished product

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

3. Assembly(集合 ) the CD case and the base

1

2

3

4

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

4. making the coil by the copper wire

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

5. assembly to the CD case

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

5. assembly to the CD case

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

6. making the rotor(轉片 )

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

6. making the rotor (轉片 )

1

32

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

7. making the turbine(渦輪 )1

2 4

3

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

7. making the turbine (渦輪 )

5

6

7

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Making Process-製作過程

8. assembly all the component(部件 )

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Final Product-製成品

Finish!!

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Calculation相關計算

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Power(功率 ) of Wind turbine

kinetic energy of a mass in motions is:

The power in the wind is given by the rate of change of energy:

As mass flow rate is given by:

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Power (功率 ) of Wind turbine

Also, the rate of change of distance is given by:

we get:

Hence, the power can be defined as:

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Power (功率 ) of Wind turbine

Power coefficient(功率系數 ),

Cpmax = 0.59

Therefore, the extractable power:

Picture captured from http://www.eoearth.org/article/Betz,_Albert

German physicist Albert Betz

No wind turbine can convert(轉換 ) more than 16/27 (59.3%) of the kinetic energy of the wind into mechanical energy turning a rotor.

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Power (功率 ) of Wind turbine

For this turbine,

假設 ,Power Coefficient(功率系數 ), Cp = 0.5Air density(密度 ), ρ = 1.23 kg/m3

Area of blades(扇葉 ), A= 0.04*0.2 = 0.008 m2

Wind speed(風速 ), v = 20km/h = 5.56 m/sec所以 , P = ½*0.5*1.23*0.008*5.563

= 0.423 W

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Induced voltage-感生電壓

Since,

Thus,

種類 數值N ( 線圈圈數 ) 200

B ( 磁場強度 ) 0.5T

r ( 線圈半徑 ) 0.015m

И ( 線圈數目 ) 4

Δt (週期時間 ) 0.2s

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Induced voltage-感生電壓

Normally, an AA battery(電池 ) is having 1.5V

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Applications(應用 )

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Factor (影響因素 )

Factor(影響因素 ) of output voltage:Wind speed(風速 )Strength of magnet(磁石強度 )

*The number of turns of coil, N(線圈圈數 )*Internal resistance of wire, r(電線內阻 )Since因為 N ->r ,Iout

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

延伸探究

內阻同圈數對於輸出電流的連帶關係

計算輸出功率

計算效率

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

Demonstration-演示

This work by Chak Chun Hang of the Department Applied Physics, The Hong Kong Polytechnic University is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Hong Kong License To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/hk/deed.en_HK

完