June 1, 2011

The T-Point Plant: The Ultimate Validation Test

By Angela Neville, JD

Validating Upgraded Components During Periods of Low Demand

MHI uses periods of low demand to inspect the plant’s equipment and to introduce upgraded components intended to promote enhanced reliability and performance, Koeneke said.

Designers and research and development staff based in nearby buildings have the ability to request the installation of temporary sensors that allow them to gather valuable insights pertaining to the modified parts. They have the invaluable opportunity to see immediate, first-hand results of their modifications and review their ideas to develop even better designs. Numerous improvements to the G-Series fleet of gas turbines were validated at the T-Point plant and consequently resulted in the high reliability this class enjoys.

Another Milestone: Demonstration of the M501J Gas Turbine

In November 2010, after T-Point staff completed validation of the air-cooled M501GAC gas turbine, they replaced this frame with the first M501J gas turbine (Figures 2 and 3). T-Point has achieved another unprecedented milestone with the ongoing demonstration operation of this turbine, which has a inlet temperature of 1,600C (2,912F). That’s 100C higher than the current highest-temperature engine.

2. Traveling turbine. The M501J gas turbine is prepared for transportation to the T-Point plant for validation testing. Courtesy: MHI

3. Making the mark. The T-Point achieved another unprecedented milestone with the ongoing demonstration operation of the M501J gas turbine, which has a turbine inlet temperature of 1,600C (2,912F). Courtesy: MHI

The 60-Hz J-Series turbine achieves a rated power output of about 320 MW (ISO basis) and 460 MW combined-cycle power generation. According to MHI, this new gas turbine is able to withstand temperatures 100 degrees higher than the company’s existing 1,500 C-class G-Series gas turbine because of a low-thermal-conductivity thermal barrier coating technology and improvements in cooling efficiency. The adoption of an enhanced three-dimensional design contributes to improved aerodynamics. In the J-Series gas turbine, the compressor is designed to provide a higher compression ratio, while the combustor carries on the steam-cooled technology originally developed for the G-Series turbine.

“We have rheostat capabilities at Takasago Machinery Works, but it is naive... to assume that the short-term shop test operations with or without off-frequency operations can replace true validation under ‘demand conditions,’” Koeneke said. However, “Validation should replicate as much as possible the operating conditions the equipment will be exposed for years to come, and no demonstration plant in the world has achieved this task better than the T-Point Plant.”