پاورپوینت در مورد توربینهای بادی (pptx) 35 اسلاید

دسته بندی : پاورپوینت

نوع فایل : PowerPoint (.pptx) ( قابل ویرایش و آماده پرینت )

تعداد اسلاید: 35 اسلاید

قسمتی از متن PowerPoint (.pptx) :

Ken Youssefi Engineering 10, SJSU 1 Wind Power and Wind Turbines ENGR 10 San Jose State University Ken Youssefi Engineering 10, SJSU 2 Alternative Sources of Energy Solar Power Ken Youssefi Engineering 10, SJSU 3 Wind Turbine Energy Ken Youssefi Engineering 10, SJSU 4 Wind Turbine Wind energy is created when the atmosphere is heated unevenly by the Sun, some patches of air become warmer than others. These warm patches of air rise, other air rushes in to replace them – thus, wind blows. A wind turbine extracts energy from moving air by slowing the wind down, and transferring this energy into a spinning shaft, which usually turns a generator to produce electricity. The power in the wind that’s available for harvest depends on both the wind speed and the area that’s swept by the turbine blades. Ken Youssefi Engineering 10, SJSU 5 Two types of turbine design are possible – Horizontal axis and Vertical axis. In horizontal axis turbine, it is possible to catch more wind and so the power output can be higher than that of vertical axis. But in horizontal axis design, the tower is higher and more blade design parameters have to be defined. In vertical axis turbine, no yaw system is required and there is no cyclic load on the blade, thus it is easier to design. Maintenance is easier in vertical axis turbine whereas horizontal axis turbine offers better performance. Wind Turbine Design Horizontal axis Turbine Vertical axis Turbine Ken Youssefi Engineering 10, SJSU 6 Main components of a Wind Turbine Ken Youssefi Engineering 10, SJSU 7 What should be the angle of attach? What should be the blade profile? Conduct an internet search to obtain enough information to help you decide on the number and profile of the blades. How many blades to use? Blade Length Blade Number Blade Pitch Blade Shape Blade Materials Blade Weight Rotor Blade Variables Ken Youssefi Engineering 10, SJSU 8 Wind Turbine For the drag design, the wind literally pushes the blades out of the way. Drag powered wind turbines are characterized by slower rotational speeds and high torque capabilities. They are useful for the pumping, sawing or grinding work that Dutch, farm and similar "work-horse" windmills perform. For example, a farm-type windmill must develop high torque at start-up in order to pump, or lift, water from a deep well. Drag Design Blade designs operate on either the principle of drag or lift. Ken Youssefi Engineering 10, SJSU 9 Wind Turbine The lift blade design employs the same principle that enables airplanes, kites and birds to fly. The blade is essentially an airfoil, or wing. When air flows past the blade, a wind speed and pressure differential is created between the upper and lower blade surfaces. The pressure at the lower surface is greater and thus acts to "lift" the blade. When blades are attached to a central axis, like a wind turbine rotor, the lift is translated into rotational motion. Lift-powered wind turbines have much higher rotational speeds than drag types and therefore are well suited for electricity generation. Lift Design