The
1,836MW Xiaolangdi Project was completed in 2000, one year ahead of schedule,
and is now generating 5.1 billion kWh of electricity a year. The World Bank
reports total costs to have been $3.5 billion ($700 million lower than
projected), with $1 billion on resettlement costs for about 200,000 people.
Xiaolangdi
Project, a key Chinese national project, is located 40km north of the ancient
city of Luoyang in central China's Henan Province. The project is the largest
of its kind on the Yellow River, and is second only to the Three Gorges project
on the Yangtze. It consists of underground generating units, silt-discharge
channels and a 1,317m-long, 154m-high dam.
MULTIPURPOSE
DAM PROJECT
Xiaolangdi
is a multi-purpose project for flood control, ice control, dredging, industrial
and municipal water supply and hydroelectric power. The region surrounding the
lower reaches of China's second longest river is densely populated and a major
agricultural area. It has been subjected to devastating Yellow River floods,
which China is determined to end. Xiaolangdi is one of 27 dams planned for the
river.
Yellow
River projects are especially challenging because of local conditions. Rapid
loss soil erosion upstream builds up into high sediment levels downstream. This
raises the river bed and causes floods.
The
project's 12.8km³ reservoir extends for 130km. It is designed to trap sediment
for the first 20 years of operation and then reach equilibrium. A complex
system of 15 large tunnels with an underground powerhouse makes it possible to
flush sediments by creating controlled floods in the main river channel. Three
silt-discharge tunnels were completed ahead of schedule in spring 1999 to
ensure the project could cope during the summer flood season.
HYDRO
TURBINES, GOVERNORS AND GATES
Voith
supplied the six hydro turbines, governors and gates for Xiaolangdi. During the
flood season the units will operate with sediment-laden flow under extremely
hostile conditions. Pioneering coating techniques have been employed to protect
the components from erosion in the heavily silt-laden water.
The
plant will only be utilised at full capacity at periods of peak demand and
during the flood season. At most times only two of the six generators will be
on line to limit water discharge to 400m³/s.
While
much of the Voith equipment was manufactured at the company's plant in York,
USA, the group's new Chinese joint venture, Shanghai High-Technology Equipment
Company (SHEC), also produced equipment for the project. (Voith and Siemens
both support SHEC). Harbin Electric Machinery Co Ltd supplied the six 333MVA
generators and Dongfang Electrical Machinery also supplied electrical
equipment. Elin Energieversorgung of Austria engineered and supplied control
and monitoring equipment.
XIAOLANGDI
PROJECT LAYOUT
Because
the Xiaolangdi project had to meet a number of objectives the layout of the
scheme is very complicated and rather different from straightforward hydropower
plant.
The
underground power room and all water conveyance tunnels are located in the left
bank, which resulted in a complex layout and closely spaced underground
excavations. The underground powerhouse complex consists of a 251.5m-long,
26.2m-wide and 61.44m-high powerhouse, a 150m-long, 15.2m-wide and 18.3m-high
transformer chamber and a 15m-long, 15m-wide draft tube gate chamber. Six draft
tube tunnels discharge into the draft tube gate chamber and three 12m-wide,
19m-high tailrace tunnels exit from the gate chamber.
HYDROPOWER
PROJECT COSTS
The
total projected cost was $4.2 billion. The World Bank approved debt finance for
the project in 1994, covering around 44% of the value of contracts with foreign
construction groups. The $570 million Xiaolangdi loan is the Bank's most
important Chinese commitment. The US Export-Import Bank provided $58 million to
cover US exports of turbines. Chinese state and provincial bodies funded the
remainder of the project.
The
power plant's capacity is 1,836MW (six 306MW Francis turbines), generating 5.1
billion kWh of electricity a year. Preparatory work began in 1991. Main orders
were placed in 1993 and 1994. One of the landmark events of the project
involved diverting the Yellow River. This took place on 28 October 1997 and
became a national occasion. The dam received state approval and started storing
water in October 1999. The project was completed in 2000.
YELLOW
RIVER WATER AND HYDROELECTRICPOWER DEVELOPMENT CORPORATION.
The
Yellow River Water and Hydroelectric Power Development Corporation (YRWHDC) is
responsible for the project, which was designed by the Reconnaissance,
Planning, Design and Research Institute (RPDRI) in Zhengzhou, Henan. The
Xiaolangdi Engineering Consulting Company (XECC) has been set up to manage the
overall project and to provide site supervision. These three companies are all
responsible to the Ministry of Water Resources of China. The Canadian
International Project Managers (CIPM) Ltd are acting as consultants to the
employer.
CONSTRUCTION
CONTRACTS
Three
European-led international joint venture companies split the construction
contracts. The contracts, worth a total of $883 million according to World Bank
estimates, were let in 1994.
Yellow
River Contractors, formed by Impregilo, Hochtief, Italstrada and Bureau 14, won
the construction contract for the river closure works, the 51.8m x 106m main
dam and associated structures. Xiaolangdi Joint Venture, comprising Dumez,
Philip Holzman and Construction Bureau 5, won work related to the underground
power structures. CGIC, a joint venture of Ed Zublin, Strabag, Wayss &
Freytag, Del Favero, Salini and Bureaux 7 and 11, won the contract for intake
and outlet works, the tunnels which discharge water and sediment and the flood
overflow. Spie Batignolles has since replaced Del Favero. Early problems and
disputes for the Zublin group, which initially delayed progress, have now been
resolved.
HYDROPOWER
IN CHINA
China
plans to increase its electric power capacity by between 8% and 9% per year to
meet growing demand from both industry and private consumers. More than 17% of
China's total electricity production is supplied by hydropower, but only about
15% of the country's technically feasible hydropower potential has been
developed to date. 24 hydropower-generating units with a combined capacity of
5,300MW came on stream in China in 1999. This increased the installed
hydropower capacity by 8.3% to almost 70,000MW at the start of 2000.
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