Rolls-Royce is introducing a new higher powered addition to its industrial RB211 family of gas turbines – the sixth generation of this well established machine – further building on technologies employed in the Trent 60, in particular its combustor system, high-pressure turbine rotor blades and intermediate-pressure compressor stators and rotors, with the aim of “combining the best features” from both engines, says Steve Richards, Rolls-Royce RB211 product director.
Called the H63 it will be initially rated at 44 MW with a WLE (wet low emissions) combustion system and 38 MW in the DLE (dry low emissions) version, filling “a power gap in the industry not fully covered by other gas turbines”, says Rolls. The new engine is considered to have the potential for further upgrades, with a rating of 50 MW (WLE version) possible in the future.
In the WLE version simple cycle efficiency will be 41.5% (heat rate 8679 kJ/kWh, 8228 Btu/kWh), which Rolls-Royce describes as “the best in the 35 MW to 45 MW power range.”
The industrial RB211 gas turbine was introduced in 1974, and since then more than 600 have been sold, with a total of 26 million operating hours accrued. It was initially rated at 24 MW, but continuous development has seen the power rise to 32 MW in its latest manifestation (the GT61 model), introduced in 2001, which itself incorporated elements of compressor and turbine technology from the Trent.
The H63 (WLE) represents a further 30% increase in power, with the same footprint. Contributing to this are specific additional technologies taken from the Trent: the IP compressor blading and discs, which provide the power and efficiency required for the H63; Trent combustor technology, which is common to the industrial Trent 60 and the aerospace Trent 800, introducing WLE capability and compatibility with H63 power levels; and the Trent high pressure turbine, providing the efficiency and longevity needed for the H63.
With the H63, the Rolls-Royce industrial RB211 range will extend from 29 MW (for the lowest rated machine) “to a possible 50 MW”, neatly dovetailing with company’s industrial Trent models, which go from 51 MW to 64 MW in simple cycle and up to 107 MW in combined cycle.
The RB211-H63 WLE (Wet Low Emissions) will be ready to enter service in early 2012, with the first sale expected to be for an onshore power installation. The DLE (Dry Low Emissions) option will be made available from 2013.
The ability of the H63 to start rapidly – from cold to full power in ten minutes – , and to follow load, with good cycling performance and minimal life degradation, mean “it is a great complement to renewable power generation sources which are inherently intermittent and unpredictable”, says Rolls-Royce, describing it as “a great fit for these applications.”
The new machine is capable of changing between liquid and gas fuels at all power levels without any interruption to load. But the company is bullish about the outlook for natural gas: “Recent advances in the production of natural gas leads most analysts to forecast that there should be ample supply of affordable natural gas way into the future. Coupled with the fact that the fuel emits less carbon dioxide than other fossil fuels, means electric power operators in a carbon-constrained environment are likely to consider gas fired power stations.”
The new gas turbine consists of two main parts, in Rolls-Royce parlance the “gas generator” and the “power turbine”. The RB211-H63 gas generator is being developed by Rolls-Royce engineers in Montreal, Canada, Mount Vernon, Ohio, USA and in the UK at Ansty near Coventry, with final assembly and testing of the first unit scheduled to take place in Montreal in November 2010. Development of the two-stage power turbine (designated RT 63) is running in parallel with this.
The first complete genset package will be engineered, assembled and tested at Rolls-Royce’s Mount Vernon packaging facility, with package testing scheduled for completion in early 2011.