Jurong Island CCGT Plant, Singapore

The 500MW combined-cycle plant now being commissioned on Jurong Island will help power to the Singaporean network. The $525m plant is located in the Tembusu sector of Jurong Island, close to several potential customers.

Keppel Merlimau Cogen Pte Ltd. (KMC) awarded Alstom the €170m contract to build the turnkey dual-fuel (gas/oil) plant. Alstom designed, constructed and is commissioning the plant. It has also supplied two GT13E2 gas turbines, two heat-recovery boilers, one steam turbine and associated equipment.

Construction started on 31 March 2005, and the plant will be operated by KMC. The project will provide utilities like steam, firefighting water, cooling water and pipe corridor services (Pipenet) to consumers on Jurong Island. It will be fuelled by imported natural gas, with auto-switchover to diesel standby firing.

DEVELOPMENT OF GT13E2 GAS TURBINES

The first GT13E turbine, commissioned in 1987, used a 21-stage compressor and a five-stage turbine, both with low stage loading. Compressor and turbine sections were arranged on one common rotor with journal bearings.

The rotor itself was welded from a number of forged disks, resulting in a stiff and maintenance-free design with a long lifetime. A single 'silo' type combustor with a large single burner provided for a rugged and flexible engine, which is still in service today.

The need for higher thermal efficiency and dry-low NOx technology with emissions below 25ppm led to the development of the GT13E2 in 1991. This engine retains the fundamental aerodynamic and mechanical design features of the GT13E as well as many of its parts. The new design uses Alstom's EV (EnVironmental) dry-low NOx burner with annular combustor to replace the GT13E's single, top-mounted 'silo' combustor. The resulting improvement in hot gas temperature distribution raised the turbine inlet temperature, increasing the compressor pressure ratio from 13.9:1 to 14.6:1.

These modifications yielded a GT output of some 165MW and combined cycle efficiency values of more than 53% (triple pressure configuration). Some 70 units in commercial operation have now accumulated more than two million operating hours.

New GT13E2 turbines incorporate further technical enhancements. M configuration (performance optimised) types feature an ISO performance rating of 172.1MW at 36.4% simple cycle efficiency on natural gas. They have 53.1% combined cycle efficiency if matched with a dual pressure water/steam cycle configuration (with two gas turbines and one steam turbine). In the Juron project, they operate in a 2x2x1 arrangement to generate 500MW.

Alstom has also been awarded an 18-year operation and maintenance contract for the site, covering scheduled and unscheduled maintenance as well as operation and maintenance support.

FULL OUTPUT EXPECTED DESPITE OVERCAPACITY

Singapore has no domestic oil reserves, but local companies have invested in overseas exploration and production of oil and gas reserves. One of these companies is Singapore Petroleum Company Ltd. (SPC), which will supply diesel to the plant.

Keppel Merlimau Cogen (KMC) was specially formed to develop, build, own and operate the greenfield Jurong Island plant. This will increase Singapore's power generating capacity to nearly 10,000MW; almost double the present peak demand of 5,100MW. Senoko Power and PowerSeraya supply about a third of this each, with the rest coming from Tuas Power and SembGas Cogen. Keppel expects the plant to produce to full capacity, despite Singapore’s current overcapacity.

The plant is expected to be one of the more cost efficient and flexible power generators in the market. The project secured limited recourse financing at end March 2005. A loan package financed 100% of total project costs, with a 16-year term loan and a two-year equity bridge loan.

HSBC Project and Export Finance (PEF) originated the deal and coordinated the execution with joint lead arrangers Calyon, ING Bank and Sumitomo-Mitsui Banking. HSBC PEF also undertook the role of documentation bank.