JP-7856937-B2 - Method for manufacturing columnar floating structures

Inventors

• 十川 靖弘
• 西郡 一雅
• 高橋 智彦
• 石川 哲哉

Assignees

• 東京電力ホールディングス株式会社

Dates

Publication Date

20260512

Application Date

20211220

Claims (3)

1. In a method for manufacturing columnar floating structures that constitute a floating offshore wind power generation facility, The cutting process involves cutting out a flat surface material from the base material, An end bending process is performed to obtain a bent face material including a flat portion and a bent portion by bending one end of the aforementioned face material, A placement step of arranging multiple bent surface materials so that they are butted together at a predetermined intersection angle, The system includes a connecting step of welding together the bent face materials that have been arranged in the arrangement step, By butting the flat portion and the bent portion of adjacent bent surface materials together and then connecting a plurality of these bent surface materials in the circumferential direction, a hollow columnar column body is manufactured. A method for manufacturing a columnar floating body, characterized by the features described herein.
2. In a method for manufacturing columnar floating structures that constitute a floating offshore wind power generation facility, The cutting process involves cutting out a flat surface material from the base material, An intermediate bending process is performed to obtain a bent face material that includes two flat sections and a bent section formed between the flat sections, by bending the intermediate section of the aforementioned face material. A placement step of arranging multiple bent face materials so that they are butted together, The system includes a connecting step of welding together the bent face materials that have been arranged in the arrangement step, A hollow, columnar column body is manufactured by butting together adjacent bent face materials such that their flat surfaces are on the same plane or substantially on the same plane, and then connecting a plurality of these bent face materials in the circumferential direction. A method for manufacturing a columnar floating body, characterized by the features described herein.
3. In a method for manufacturing columnar floating structures that constitute a floating offshore wind power generation facility, The cutting process involves cutting out a flat surface material from the base material, A bending process to obtain a bent face material including two or more bent sections by bending the aforementioned face material at two or more locations, A placement step of arranging multiple bent face materials so that they are butted together, The system includes a connecting step of welding together the bent face materials that have been arranged in the arrangement step, By butting the ends of adjacent bent face materials together and then connecting multiple bent face materials in the circumferential direction, a hollow columnar column body is manufactured. A method for manufacturing a columnar floating body, characterized by the features described herein.

Description

This invention relates to a columnar floating structure that constitutes a floating offshore wind power generation facility, and more specifically, to a columnar floating structure having a column body with a polygonal cross-sectional shape having a curved top, and a method for manufacturing the same. Electricity consumption in Japan, although initially declining due to the 2008 global financial crisis, has been continuously increasing since the 1973 oil shock, expanding 2.6 times between fiscal years 1973 and 2007. This increase is attributed to factors such as the widespread adoption of home appliances like air conditioners and electric carpets due to improved living standards, and the proliferation of office automation (OA) equipment and communication devices accompanying the increase in office buildings. Until now, the enormous demand for electricity has been primarily supported by power generation using fossil fuels such as oil and coal. However, in recent years, concerns have been raised about the depletion of fossil fuels and environmental problems associated with global warming, and in response, power generation methods have gradually changed. As a result, while power generation using oil and coal accounted for approximately 90% of the total around 1973, as explained earlier, that proportion had decreased to 66% by 2010. Instead, nuclear power generation, which now accounts for slightly over 10% of the total (2010), has increased. Nuclear power generation has made a significant contribution to Japan's electricity demand because it has a remarkable effect in reducing greenhouse gas emissions compared to conventional power generation methods and can provide electricity at a low cost. Furthermore, renewable energy power generation methods are increasingly being adopted because they can reduce greenhouse gas emissions. These renewable energy sources, such as solar, wind, geothermal, small-scale hydropower, and woody biomass, are literally renewable and are expected to be promising low-carbon energy sources because they reduce greenhouse gas emissions and can be produced domestically. Among renewable energy sources, wind power generation, in particular, boasts high efficiency in converting electrical energy. Generally, while the conversion efficiency of solar power is approximately 20%, woody biomass power is about 20%, and geothermal power is 10-20%, wind power is said to be 20-40%, meaning it can convert energy into electricity more efficiently than other power generation methods. Furthermore, unlike solar power, wind power can generate electricity day and night, which is another key feature. Due to these characteristics, wind power is already widely used as a major power generation method in Europe, and in Japan, as part of its "energy mix" initiatives, it aims to account for 1.7% of the power source mix by 2030. Wind power generation is broadly classified into onshore wind power generation and offshore wind power generation depending on the installation location. Onshore wind power generation is easier to install than offshore wind power generation, and therefore has the advantage of lower costs. On the other hand, offshore wind power generation does not suffer from the noise problems associated with onshore wind power generation, avoids the risk of damage from toppling, and, most importantly, can stably obtain much larger wind power than onshore wind power generation. Japan, with the world's sixth-largest exclusive economic zone, is a suitable location for floating offshore wind power generation and is considered to have the potential to become a promising source of renewable energy in the future. Furthermore, different types of offshore wind power generation are employed depending on the installation location. Fixed-bottom offshore wind power generation is suitable for areas shallower than 50 meters, while floating offshore wind power generation is suitable for areas deeper than 50 meters. Floating offshore wind power generation utilizes a floating structure that floats on seawater. The power generation mechanism is installed on the floating structure, which is connected by mooring lines, and this mechanism generates electricity. Floating structure types include pontoon type (barge type), semi-submersible type, spar type (columnar type), and tensioned-leg platform (TLP). In offshore areas far from land where large winds are expected, the columnar type tends to be primarily adopted. Figure 16 is a schematic side view of a columnar offshore wind power plant. As shown in this figure, a columnar offshore wind power plant consists of a columnar floating structure (spar-type floating structure) floating in the sea, and a tower, rotor, nacelle, etc., installed on top of it. The tower is a structure that supports the rotor and nacelle, and the columnar floating structure functions as the base of the tower. The rotor, consisting of blades and a hub, converts wind into power, and the nacelle, containing a ge