Thermal City

당인리 화력발전소 공원화 현상설계

2013

Project Location: Seoul Korea

This park prepares against climate change. The site is where currently the Danginri Combined Heat Plant stands, Korea’s first thermal power station, which will be put into underground . The flow of landforms is the result of the close and intensive collaboration with Arup which will create a more comfortable microclimate in summer and winter for park users, with the help of the dynamic air circulation of the riverfront. The back-and-forth design process with engineers was the key to the authentically sustainable and ecological scheme: the nature of the generating system and the site location were carefully researched and considered throughout the design process, such as climate data of the site and hot water waste from the generator.
Danginri is a combined heat plant (CHP) located along the Han River of Seoul built in 1930, and now generates 3.4 billion kWh of electricity per year. Approaching its expiration, it is to be rebuilt under its current location, while the ground of 25 acres will become a public park for which this scheme is proposed. To the north of the plant, there is a vibrant community called ‘Hongdae’, famous as an entertainment district for the young.
It was hot and humid in summer and cold and dry in winter in Seoul. It gets even more drastic due to climate change over the past few years, so the period of comfortable outdoor life is getting shorter every year. The Thermal City aims to provide a public space that is cooler in summer and warmer in winter by implementing a set of climate-sensitive design concepts. Especially the first two were drawn through intimate collaboration with engineers specialized in sustainability, ecology, and climate change.
The scheme aims to control temperatures within the open space, observing that the challenging winter and summer seasons experienced in Seoul are lengthening, minimizing the thermally comfortable spring and autumn seasons. Topographic valleys, inspired by the once present sand dunes of the Han river, are aligned to maximize cool summer air flows and, combined with vegetation, provide barriers to the winter winds. In a major design innovation, excess heated water from the underground power station runs through pipes located under stone surfaces within the park before expelling into the river as cool water. This feature has two functions; to address the ecological damage of pumping hot water directly into the river (a common practice in power stations), and to provide warm seats and microclimates within the park in winter. This technique references ‘ondol (or gudeul)’ found in traditional Korean architecture, where heat from wood smoke is applied under a thick masonry floor to heat sleeping and living areas.
The park also produces its own energy through a solar canopy over the car park and wind turbines located throughout the park. It is also self-sufficient in water supply for irrigation, with the help of the bio-swales along with the landforms and detention ponds near the river.
The landforms were grouped by many pedestrian paths intended to bring the urban flow
into the park and to the riverfront. Since there is no physical fencing along the park’s periphery, the road at the northern edge is a very attractive destination for the already vibrant community to stretch out. The area is supposed to become more pedestrian-oriented at the end.
A software called ‘Ecotect’ was used to bring more sophistication to the design. The orientation and size of landforms were modified several times according to the result of the test. Most importantly, the simulation through a Thermal Sensation Index equation verified the effectiveness of the space by inputting temperature, solar radiation, and wind speed of a certain time.
TSI[i]= 1.2 + 0.1115*Ta + 0.0019*SR – 0.3185*WS
( Ta : temperature, SR : solar radiation , WS : wind speed )
This index establishes a reading of 4 out of 7 as most comfortable, with 3 to 5 as the acceptable the level of comfort. The simulation was to test the design for June 2-5 pm (summer) and Dec 2-5 pm (winter), comparing site conditions before and after design implementation. As shown in the results, during the summer months the design extends comfort areas from predominantly building shadows into the central open space. In winter, the simulation result showed, while the mounds are beneficial during summer, the valley created between landforms could expedite wind velocity and worsen the thermal comfort partially: in response, the heated stone seats were strategically placed on the south-eastern slopes without any shades in order to make the less cold area warmer.

[i] * Givoni, B., M. Noguchi, H. Saaroni, O. Pochter, Y. Yaacov, N. Feller and S. Becker (2002) Outdoor comfort research issues. Energy and Buildings, Vol.1462, pp.1-10