風能是一種自然界取之不盡,用之不竭的的清潔能源。隨著傳統(tǒng)能源的日益消耗,以及隨之而來的環(huán)境污染日趨嚴重,風能利用成為各個國家節(jié)能減排的工作重點之一。
風力發(fā)電技術,經過長時間的技術積累和市場應用,成為人們利用風能的最主要方式。與此同時借助風力機發(fā)熱成為了繼風力發(fā)電之后的又一個很有發(fā)展前景的方向。和風力發(fā)電機一樣,風力發(fā)熱系統(tǒng)同樣面臨在各種工況下的控制問題,而制動系統(tǒng)首當其沖,成為了風力機安全與可靠性問題極為重要的一環(huán)。除了在風力機的旋轉主軸上安裝各式各樣的機械制動器,人們還 發(fā)了空氣動力制動系統(tǒng)。而且空氣動力制動系統(tǒng)由于其自身的使用特點,成為現(xiàn)代風力機制動系統(tǒng)中必不可少的組成部分。
本文主要研究了垂直軸阻力差型風力機在極限工況下的氣動制動問題,有效的降低風力機所承受的風壓,維護風力機本身的安全。借鑒水平軸風力機的變槳機構,通過變槳功能來完成功率的調節(jié)和空氣動力的制動原理,在垂直軸風力t幾上通過調節(jié)葉片的角度來調整風能利用率,達到制動之目的。
本文針對國內垂直軸阻力差型風機氣動制動系統(tǒng)研究不足的問題,具體的給出了一種垂直軸阻力差型風力機可轉動葉片通過安裝扭轉彈簧來控制和調整葉片偏轉角度的方案。目的是降低葉片在極限工況下的受力面積,從而保證葉片在排解掉一部分風壓后,保證葉片的結構安全。設計了滿足在極限工況下,控制葉片最大偏轉角度的扭轉彈簧。
并且本文也將風力機與永磁渦流發(fā)熱機進行了匹配實驗研究,通過實驗研究驗證了葉片氣動制動應用的可行性,為垂直軸風力機氣動制動奠定了基礎。
Abstract
Wind energy is a inexhaustible clean energy. With the increasing consumption ofconventional energy,environment pollution get more and more serious consequently, windenergy utilization has become one of the priorities of energy saving all aroud the world. Aftera long period of technology accumulation and market application,wind electricity has becomethe main way of wind energy utilization. At the same time, wind heating system become apromising direction . Meanwhile,wind heating system is also facing controlling problems atthe variety conditions. The braking system bear the brunt of the wind turbine safety issues.Mechanical brake can be installed on the wind turbine's rotating spindle. Aerodynamicbraking system is also developed for brake system. And because of its features, aerodynamicbraking system has become the integral part of the modern wind turbine.The main work of this thesis is to achieve a pneumatic brake for differential resistancetype of vertical axis wind turbine in the limit conditions. Reducing exposure to the windeffectively, wind turbine maintenance and safety has been promised. According to thehorizontal axis wind turbine pitch organization,the aerodynamic braking function can berealized. So the vertical axis wind turbine can also adjust the angle of the blades to completethe utilization of wind energy .
In this paper, a rotatable blade system of resistance type vertical wind turbine is given,torsion spring can achieve good control of the blade angle. The purpose is to reduce the windpressure on the blade and ensure the structural safety of the bladeat the limit condition.Torsion spring is designed to meet the limit conditions, the maximum rotating angle is undergood control . And wind turbine has been matched with permanent magnet eddy currentheating machine, experimental study to verify the feasibility of the blade aerodynamic brakingsystem. All these works have laid a good foundation for future research and applications ofwind turbine Pneumatic brake.
Keywords: Wind Energy Utilization, The Rotatable Blades, Torsion Spring, Pneumatic
Brake,Matching Problem.