2011年度香港理工大學交換學生課程設計性實驗報告

1、風力發(fā)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HKPUApplied Physics StudentChka Chun Hang,目錄,引言理論發(fā)電機的設計製作過程相關計算演示,Where do winds come from?風從哪裡來?,Because of the temperature dif

2、ferences(溫差) around the world,,Surface Wind,Convection updraft of rising warm Air,What is wind turbine(風力發(fā)電機)?,Wind’s kinetic energy(動能) ->electrical energy(電能),,Theory理論,By Lenz’s Law (冷次定律) Induced current(

3、感生電流) opposes (對抗) the change of the magnetic force Heinrich Lenz 海因里希·冷次,,Theory理論,Theory理論,Induced emf-感生電壓,Where ,N is the number of turn of coil,B is the magnetic field strength(磁場

4、強度)A is the area(面積) of the coil,,,,,,,,,,,,Design-設計,,Design-設計 (3D View),,Design-設計 (3D View),,Brace 支架,Design-設計 (3D View),,Axle 軸,Design-設計 (3D View),,Turbine 渦輪,Design-設計 (3D View),,Rotor 轉片,Design-設計 (3D View),,C

5、oil 電線圈,Design-設計 (3D View),,Supporting Base支撐底部,Design-設計 (3D View),,Magnet 磁鐵,Material-物料,Screw(螺絲) x 8Bearing(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

6、樽)Magnet (磁石)x 4LED 燈x 1CD case x 1),Making Process-製作過程,1. Preparing the material,Making Process-製作過程,2.making the frame(骨架) and base,1,2,3,Making Process-製作過程,Finished product,Making Process-製作過程,3. Assembly(

7、集合) the CD case and the base,1,2,3,4,Making Process-製作過程,4. making the coil by the copper wire,Making Process-製作過程,5. assembly to the CD case,Making Process-製作過程,5. assembly to the CD case,Making Process-製作過程,6. making t

8、he rotor(轉片),Making Process-製作過程,6. making the rotor (轉片),1,3,2,Making Process-製作過程,7. making the turbine(渦輪),1,2,4,3,Making Process-製作過程,7. making the turbine (渦輪),5,6,7,Making Process-製作過程,8. assembly all the component

9、(部件),Final Product-製成品,Finish!!,,Calculation相關計算,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:,,,,,P

10、ower (功率) of Wind turbine,Also, the rate of change of distance is given by:we get:Hence, the power can be defined as:,,,,Power (功率) of Wind turbine,Power coefficient(功率系數(shù)),Cpmax = 0.59 Therefore, the extract

11、able 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

12、 turning a rotor.,,Power (功率) of Wind turbine,For this turbine,假設 ,Power Coefficient(功率系數(shù)), Cp = 0.5Air density(密度), ρ = 1.23 kg/m3Area of blades(扇葉), A= 0.04*0.2 = 0.008 m2Wind speed(風速), v = 20km/h = 5.56 m/se

13、c所以, P = ½*0.5*1.23*0.008*5.563 = 0.423 W,Induced voltage-感生電壓,Since, Thus,,,,,,,,,Induced voltage-感生電壓,Normally, an AA battery(電池) is having 1.5V,,,,,Applications(應用),,Factor (影響因素),Factor(影響因素) of output