Weight optimized tower segments as an example for lightweight design of large-scale products

Theme
XXL products
Project title Weight optimized tower segments as an example for lightweight design of large-scale products (LeiTu)
Project duration 01.07.2010 – 30.06.2012
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Increasing the performance of wind power plants is possible by rising hub heights. However, the risk of tower failure rises with tower height and mass. It was the aim of this research project to develop news concepts which enable the reduction of the tower mass of onshore wind power plants and thus enable higher tower constructions. A variety of different approaches, e. g. from bionics, aerospace and automotive sector, have been researched and transferred to wind power plant towers. The developed light-weight tower concepts showed the possibility to reduce tower mass by 20 % compared to existing tower constructions.

Publications about the project

The range of structure sizes for industrial products produced today is increasingly expanding. This trend is evident in both small-scale (e.g. semiconductor applications) and large-scale (e.g. wind turbine rotors) products. While definitions already exist for smaller scale device structures, the conceptual distinction between conventional large products and large scale products is currently insufficient. In this study, we present a potential basis for the definition of large scale products. To achieve this, we derive hypotheses and examine these in the context of an empirical study using the examples of several sample products. It is shown that the transition from conventional products to large scale products is characterized by a disproportionate increase in product costs due to the augmentation of a characteristic product feature. Eventually we derive a proposed definition which characterizes large scale products in the field of production engineering.

xxl-product, large-scale, xxl, definition

By increasing the height of wind turbine generators the usable wind energy increases exponentially. However, tower weight increases accordingly. Current tower designs limit the tower height due to the explained correlation. The application of lightweight design concepts can lead to a significant weight reduction at comparable tower stiffness. As part of a research project, lightweight design concepts have been developed. These design concepts allow a mass reduction for onshore wind turbine towers up to 20 %. In this paper, the development and results regarding these lightweight concepts are presented.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

The utilization of lightweight engineering methods for tower construction of wind turbine generators enables a weight reduction at constant stiffness. Thus an increase of the tower’s height can be achieved, while keeping its weight. Within a research project at IPH several lightweight engineering solutions from bionical, aviation and aerospace applications have been investigated. According to the developed guidelines a lightweight concept based on trapezoidal sheets can reduce the mass of a 3 MW generator of 90 m height by 20 %. In this article certain details of the construction are being presented.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

The usable wind energy increases exponentially by increasing the height of wind turbine generators. The material requirements and the tower weight increases disproportionately high by growing tower height. In current designs, the height of towers is limited. The application of lightweight design concepts in the production of wind turbine tower sections can lead to a reduction in the weight with the same tower stiffness. Therefore lightweight designs have great potential to increase wind turbine efficiency. In this paper, the results of the research for lightweight concepts and their implementation on towers and a guiding systematic approach are presented. As part of the research, design concepts have been developed. These design concepts allow the mass reduction, with constant stiffness, for the wind turbine towers on land (onshore). Several investigation loops of these lightweight designs were run. Different concepts of bionics, aviation, aerospace and automotive have been investigated for their suitability in wind turbine towers. A suitable concept was identified based on trapezoidal sheets. Using these sheets, the weight of towers can be reduced by 20 %.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

In order to achieve higher energy yields of wind turbine generator, the most expedient approach is to enlarge the tower height. By increasing the height the usable wind energy increases exponentially, but also does the tower weight. Therefore in a research study several constructional designs for lightweight tower design have been investigated. The design considered several design solutions which proved successfully in bionic, aerospace and automotive applications. FEA simulations were used to compare different structures and to estimate their feasibility. The best-fit identified constructional design is based on trapezoidal sheet. The developed design enables a weight reduction up to 20 % in comparison to standard towers.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

A smart option to increase the energy yield of wind turbine generators is to increase its height. There is an exponential increase of the usable wind energy at enlarging the tower’s height, but also an exponential increase of the tower’s weight. The application of lightweight design concepts in the production of wind turbine tower sections may lead to weight reduction while keeping the tower’s stiffness at an equal level. Here the results of a study for lightweight concepts and their implementation on towers and a guiding systematic approach are being presented. The investigated design solutions proved successfully in bionic, aerospace and automotive applications. FEA simulations were used to compare the different structures and to estimate their feasibility. The investigation’s main result is a lightweight structure which provides weight reductions up to 20 %, by using lower wall thicknesses.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

To meet the growing demand for energy, further developments are necessary in the field of renewable energies. In two research projects, engineers of IPH - Institut für Integrierte Produktion Hannover have investigated how to increase the efficiency of wind turbines.

xxl products, large-scale products, wind turbines, data mining

Enlarging the height of wind turbine generators leads to exponential increase of the usable wind energy. However the construction’s weight increases equally. Therefore a systematic approach to design lightweight towers for onshore wind turbine generators has been developed in a research project. Different concepts of bionic, aerospace and automotive origin have been used to create lightweight structures for the towers. These lightweight towers have been analyzed by FEA simulations e. g. regarding their fatigue stress. The investigation’s result is a lightweight structure which enables to build wind turbine generator towers of lower wall thickness. Thus a weight reduction up to 20 % can be achieved in comparison to standard towers.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

Next generation wind turbines are to be built higher and higher. As a result of the stronger and more regular wind in greater altitudes, more energy gain can be achieved by rising hub heights of wind turbines. However, the risk of tower failure rises with tower height and mass.

xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio

Sponsor

The project no. 11.2-76221-99-2/10 was part of the joint research project Innovations for the manufacturing of large scale products funded by the Ministry for the Economy, Labour and Transport of Lower Saxony and the Ministry for Science and Culture of Lower Saxony.

Your contact person

Dr.-Ing.

Jan Langner

Manager process technology