China expands Dezhou
During a US-China summit last year, US companies signed deals worth more than $600 million with China. The Dezhou expansion project was one of the key deals.
As the People`s Republic of China moves forward with an ambitious programme to expand its electric power system, much of the new generation capacity is expected to be provided by in-country sources. However, a significant share of the new capacity – perhaps 20-25 per cent – could result from projects involving equipment and service suppliers from outside China. One example is the 1320 MW expansion of the coal-fired Dezhou power plant in Shandong Province.
The project, the result of high-level international cooperation, will be based on two steam turbine-generators supplied by General Electric of the US and will provide power to support rapid economic growth in the Shandong region, south of Beijing.
Shandong Huaneng Power Generation Development Co. Ltd., the plant owner, is one of the leading power developers in China. The project is being financed by Shandong Huaneng, the U.S. Export-Import (Exim) Bank, and other international financial agencies.
The new expansion is Phase III of the Dezhou power plant. The first and second phases were designed by Shandong Electric Power Design Institute and constructed by the Shandong Power Engineering Construction Company. The main machines for Phase I and II were supplied by Chinese companies Harbin Boiler Works, Dongfang Turbine Factory and Dongfang Electric Machinery Factory. Phases I and II provide a total of 1200 MW of power, with the last unit going into service in late 1994.
Phase III is now under construction. When the expansion is completed in 2002, the Dezhou power station will have an aggregate capacity of 2520 MW.
Situated in the western suburbs and about four kilometres from the downtown area of Dezhou City, an important railway hub, the Dezhou Power Plant is the main power station in the Shandong power network. It has direct access both to major highways and railway coal transportation systems.
GE Power Systems signed the $160 million contract in mid-1998 to supply an integrated steam turbine island, including a broad range of balance-of-plant equipment and services, for the Dezhou expansion.
GE is supplying two 600 MW class steam turbine-generators, four boiler feed pump turbines, technical advisory services and training for the Dezhou expansion, and also is responsible for the detailed engineering design, procurement and systems integration of the balance-of-plant equipment associated with the turbine island.
Other major contractors for the project are Babcock Kraftwerkstechnik GMBR-Germany, who is providing the boiler island; and Siemens-Germany, who is supplying the instrumentation and control.
Key components of the plant expansion will include: two boiler and turbo-generating units with complete electrical and mechanical accessories, instruments and control equipment . It will also feature:
à‚-Coal handling and storage facilities
à‚-Ash disposal facilities
à‚-Fuel oil system and effluent treatment of service water and domestic water
à‚-A new 500 kV and 220 kV switchyard
à‚-Water supply system, circulating cooling water system, water pre-treatment facilities and chemical water treatment system
à‚-Associated structures such as the turbine building, control building, electrical switchgear structure, administration building, warehouse, machine shop and residential house for the operation and maintenance staff.
The large steam turbines and generators are being manufactured in GE`s turbine facilities in Schenectady, NY. The first of the two large steam-turbine generators is scheduled to begin commercial operation in the second half of 2002, followed by the second unit approximately eight months later.
The steam turbines are tandem compound design machines with reheat and four flow-down exhaust low-pressure sections. Consisting of an individual high-pressure (HP), intermediate pressure (IP) and two double flow low-pressure (LP) sections, the steam turbines will be the first GE units in China to utilize a 42-inch last stage bucket design developing generation capability of 660 MW. The steam turbines will be equipped with advanced performance packages including: improved surface finish, modern clearance rules, low solidity nozzles, optimized wheel hole sizes, additional radial tip seals, and advanced aero design and advanced clearance control for the HP, IP and LP sections. Included with the steam turbines and the GE-manufactured boiler feed pump turbines are GE`s Mark V control systems.
The boiler island supplied by Babcock Kraftwerkstechnik features drum-type boilers. The approximate furnace dimensions are: 24 m width; 16 m depth and height 63.5 m. The boiler house is 78.6 m high. Each unit is equipped with six tube ball mills including 12 classifiers.
The boiler features with opposite firing systems for burning semi-anthracite coal. The burner system includes 24 low NOx DS-burners located on six burner levels. The use of Babcock`s advanced firing technology will result in reliable and high-efficiency burning and reduced emissions.
Each boiler is designed for a continuous steam rate of 2209 t/hr at 100 per cent boiler maximum continuous rating (MCR) with a live steam temperature of of 541 degrees C and a pressure of 16.68 MPa at the turbine stop valve.
An abundant resource
Coal from Shanxi Province will be used as the boiler firing fuel, with light diesel oil No. 0 used for starting up and stabilizing combustion at low load. The coal will be transported to the project site by rail, and then by coal unloading lines inside the plant.
As an abundant fuel in the region, coal continues to be the source of much of China`s energy. About 75 per cent of the nation`s existing electric power capacity is provided by coal-fired steam plants, and it is expected that about 60 per cent of the new capacity in the next decade will be based on coal.
The new plant`s ash handling system will dispose of furnace bottom ash and fly ash. The bottom ash will be transported by a belt conveyor through an SCC process and then by truck to a bottom ash yard. Fly ash collected by electrostatic precipitator will be pneumatically conveyed to an ash silo. From there the ash can be transported either to a comprehensive re-utilization site, or to an ash yard 14 km from the plant.
The project signing ceremony in Beijing was attended by US Secretary of Commerce William M. Daley, who was in China in conjunction with a state visit by President Clinton, and several senior officials of the Chinese government. Also participating were representatives from the China National Technical Import and Export Corporation (CNTIC), the China Huaneng Group, the China Huaneng International Trade Economics Corporation (HITEC), and the Shandong Huaneng Power Development Corp.
The visit was part of a US-China summit last year during which US companies signed deals more than $600 million with China.
Robert L. Nardelli, president and chief executive officer of GE Power Systems, said the signing “highlighted months of positive cooperation among the Shandong Huaneng Power Development Corp., CNTIC, HITEC and the GE Power Systems team. The Dezhou project is the latest milestone in GE`s long-standing association with the People`s Republic of China.”