Wind turbine design project

Transcription

1 Wind turbine design project Project Description Nonrenewable resources such as coal and natural gas are the main sources of energy for many parts of the world. However, these energy resources are harmful to the environment and supplies are limited. Resources such as wind possess great potential because they are renewable and nonpolluting [1]. The client, is the Saudi ministry of water & electricity, who believes that resources such as wind possess great potential The client will base their decision on a combination of: 1. Selection of suitable locations for wind farms in Saudi Arabia. 2. Selection of the wind turbine power. 3. Design of the wind turbine rotor blades (materials and dimensions). Wind turbine design project-ie_202-

2 Design Procedure 1. Select a suitable location for wind farm in Saudi Arabia. To determine the optimal site specific wind turbine design, which is the design that results in the lowest cost of energy at that particular site? There are many decisions that have to make in designing a modern wind turbine. The optimal wind turbine design for one location is not necessarily the optimal design for another location because the wind speed distribution may vary between locations. In addition, the turbine with the highest efficiency is not necessarily the optimal turbine. It is possible for a less efficient wind turbine to have a lower cost of energy. The figure above shows a typical wind speed distribution, which can be modeled by a Weibull curve. The distribution will vary from site to site. The optimum wind turbine design is dependent on the wind speed distribution of the specific site. Wind turbine design project-ie_202-

3 2. Select the wind turbine power. The wind turbine power will depend on the total power from the wind farm and the number of wind turbines in the farm. 3. Design the wind turbine rotor blades (materials and dimensions). The wind turbine blades will be designed according to the selected wind turbine power (See handout on Useful Relations.) Deliverables Each team must communicate its final design to the client in both written and oral form. Your written team poster must contain a scaled orthographic sketch of the wind turbine. Useful relations 1. Power output from wind turbine P=Power (watts) 3 V P = ρ AC. P η 2 Wind turbine design project-ie_202-

4 ρ= Air Density (about kg/m 3 at sea level) A = Swept Area of Blades (m 2 ) V = Velocity of the wind C P = coefficient of performance η = Efficiency The maximum achievable coefficient of performance Cp max is 0.59 given by Betz limit. In practice because of tip loss, wake swirl loss and profile drag loss the value of Cp being lowered than this limiting value. For the combined effect of these three losses, Jansen and Smulders propose an expression of the form for number of blades B, tip speed ratio λ, drag to lift ratio Cd / Cl [2]. Wind turbine design project-ie_202-

5 Fig. 1 Achievable power coefficient Cp as a function of design tip speed ratio The tip speed ratio, λ, defined as the dimensionless number corresponding to the blade tip speed, ΩR, divided by the velocity of the free stream wind speed, V Where R is the blade length and Ω is the angular speed ΩR λ = V Wind turbine design project-ie_202-

6 2. Blade Design The rotor blade is a key element in a wind turbine generator system to convert wind energy into mechanical energy. Wind turbine blades must be designed to give satisfactory performances. 1. Select rotor diameter D to suit your power requirements 2. Choose a tip speed ratio λ between 5 and Decide how many blades, B, to use 80 B = 2 λ 4. The width of the blade outer portion "C", the inner part should be wider to help with starting torque. 8R C = λ 2 B 5. Calculating the blade setting angle β β = tan 1 (2R /3rλ)_ 5 References 1. J.M. Jonkman, Modeling of the UAE Wind Turbine for Refinement of FAST AD, National renewable Energy Laboratory, S A Kale and S N Sapali, Functional and Strength Design of one MW Wind Turbine Blade, PROCEEDINGS OF INTERNATIONAL CONFERENCE ON ENERGY AND ENVIRONMENT MARCH 19-21, Assessment Grading of the project will be carried out using the poster checklist and the Excel soft copy. Wind turbine design project-ie_202-