Combined cycle plants may have gone seriously out of fashion in Europe, thanks to poor economics and lack of competiveness, but they are still very much in demand in places like Korea, where another Siemens H class gas turbine has just gone into operation, at KOSPO’s LNG-fuelled single-shaft Andong plant in the province of Gyeongsangbuk-do.

There are a total of eight Siemens H class combined cycle projects in Korea, with two units in operation, Dangjin (formerly Bugok) 3, which entered operation in August 2013 (see MPS, November 2013, and September 2011), and now Andong (essentially identical to Dangjin 3).

High efficiency, short construction

High fuel efficiency remains a priority in Korea, which lacks indigenous energy resources and is one of the world’s top energy importers. According to US EIA estimates, in 2013 it was the world’s second largest importer of LNG, fourth largest importer of coal, and fifth largest importer of crude oil.

With relatively high gas prices, the ability of the H class combined cycle plant to achieve over 61% gross efficiency (ISO conditions, LHV (55%, HHV)) – equivalent to carbon dioxide emissions of about 325 g/kWh – is very attractive to the Koreans, as is the operational flexibility of the all-air-cooled machine, which is designed for 250 starts per year, with a hot start-up time of 30 minutes, from standstill to full load, a valuable feature in the evolving Korean power market.

Another attraction was fast build. Remarkably, the 417 MW Andong combined cycle plant was constructed in less than 24 months, from groundbreaking to commercial handover.

A key contributor to this achievement, which also established a new Korean benchmark in terms of health of safety, was minimising of engineering and delivery times for all components with an influence on the overall schedule. Very careful attention was paid to the supply chain and transportation routes to the site, with components coming from all over the world. In particular heavy components were scheduled to arrive at site at the same time to get the most out of heavy lifting equipment, and to minimise the time spent on preparing for heavy lifts, which can interfere with other site activities.

Also vital to the success of the project was the good working relationship between the parties involved, Siemens, GS E&C and the power plant owner/operator KOSPO (Korea Southern Power Co Ltd).

Siemens, with its partner GS E&C, was responsible for turnkey erection of the Andong plant and supply of the major components – an SGT6-8000H gas turbine, an SST6-5000 steam turbine, an SGen6-2000H generator and a Benson heat recovery steam generator (manufactured by BHI under contract to Siemens). The SPPA-T3000 I&C system and other auxiliary systems are also part of the package. In addition, Siemens has signed a ten-year maintenance contract with KOSPO.

Aiming for the top ten

A subsidiary of government owned Korea Electric Power Corp (KEPCO), KOSPO was formed in 2001 with the restructuring of KEPCO (which also saw the creation of KHNP, KOSEP, KOEWP, KWPO and KOMIPO).

KOSPO has increased its installed capacity in Korea from 5.6 GW at founding to about 9.6 GW currently (around half of which is LNG-fuelled combined cycle) – about 12% of total Korean installed capacity. The company has aspirations to become "a global top ten power company", with overseas activities currently including O&M and commissioning in the Middle East and India, and investment in Indian coal generation, and plans to further expand its international portfolio mainly in developing countries.

Under the leadership of Lee, Sang Ho, president and CEO, KOSPO is maintaining a strong track record of technological innovation. This is evidenced by its ultrasupercritical coal-fuelled Samcheok Green Power plant (see MPS, Nov 2011, pp 16-17), scheduled to enter commercial operation next year, employing the world’s largest circulating fluidised bed boilers to date, as well as its pioneering involvement with H class gas turbine technology.

In addition to Andong, KOSPO is also developing a second Siemens H class single-shaft combined cycle project in Korea, the Daegu Innovation City cogeneration facility, due to go into operation later this year. Lotte Engineering and Construction (Lotte E&C) has been contracted to build this plant by Daegu Green Power (DGP) – a joint venture between KOSPO, Lotte E&C, BHI and Daegu Gas – and has placed the contract with Siemens for the supply of main power plant components.

The continuing importance Siemens attaches to Korea was demonstrated in October 2013 when it incorporated a new company, Siemens Energy Solutions Ltd, in Seoul to act as its new regional headquarters to serve the Asian and Middle Eastern power plant markets.