Efficiency Improvement Possibilities in CCGT Power Plant Technology

Miro R. Susta

Manfred Greth

IMTE AG

Power Consulting Engineers

Switzerland

POWERGEN-ASIA 2001, KUALA LUMPUR, MALAYSIA

September 2001

ABSTRACT

Current status in the large Combined Cycle Gas Turbine (CCGT) technology is missing the instant before the first contractually guaranteed 60%-efficiency CCGT power plant comes on stream.

The biggest chances to reach this long-expected benchmark are ascribed to large heavy-duty Gas Turbine (GT) models coming from four top manufacturers at once.

These are 7001 & 9001 F & H series from General Electric (GE), ATS 501 model from Siemens Westinghouse, GT series 94.3A from Siemens Power Generation, GT24/26 from Alstom and at the last but not least the 501 / 701 F & G models from Mitsubishi Heavy Industries (MHI).

The following examples of GT technological elements are considered as promising determinants for further intensive growth in CCGT power plant thermal efficiency:

>      Turbine Inlet Temperature (TIT) reaching level of 1400°C and above.

>      Exhaust gas temperatures in the region well above 600°C.

>      Sustained improvement in special cooling techniques, especially integrated closed-loop steam cooling technique.

>      Further progress in metallurgy status, especially directionally solidified single crystal blades.

>      The use of ceramics.

>      Utilization of improved thermal barrier coatings with great durability.

>      Optimized compressor and turbine aerodynamics.

>      Advanced control system technology.

All the mentioned large industrial GTs with unit output in the range of 180 MW and above with exhaust gas temperatures well above 600°C can benefit from higher pressure and temperature supercritical heat recovery steam generator (HRSG) technology.

So we can say that commercial implementation of supercritical technology in the water-steam cycle within the frame of CCGT power plant is not any more a vision. Once-through single-pass Benson boiler using high nickel alloys for high pressure and temperature components might be employed.

Maximal utilization of process waste heat, optimization of entire CCGT cycle in respect of cooling systems, fuel supply systems and other balance of plant equipment shall also pay great contribution to highest efficiency figures.

However, 60% CCGT efficiency is only an intermediate step on the way to higher targets. The US Department of Energy’s Vision 21 program is aiming for a goal of over 70 – 75% thermal efficiency for CCGT power plants in 21^st century.

Speaker Biographical Information

(Status September 2001)  

Miro R. Susta is graduate of Swiss Federal Institute of Technology in Zurich, ETHZ; Diploma  (M.Sc.) degree in Power Plant Mechanical Engineering.

He is a Member of Swiss Engineers and Architects Association (SIA) and Member of American Society of Mechanical Engineers (ASME).

Mr. Susta has more than 27 years of professional experience in power plant design & engineering, field and factory testing, sales and marketing with Sulzer-Brown Boveri Turbomachinery AG, Brown Boveri AG, Motor Columbus Consulting Engineering AG and Asea Brown Boveri AG in Switzerland.

During his professional career, Mr. Susta accumulated a vast knowledge and experience not only in power plant design, engineering, marketing and management, but also in general power business not only in Europe but also in miscellaneous countries in Asia. 

In year 1992, Mr. Susta joined Swiss consulting engineering company IMTE AG, which is specialised in thermal power generation consulting engineering activities. Among others, he was involved in Lumut 1303MW CCGT power generation project in Malaysia from year 1993 till 1997.

At he present he is a director of IMTE AG Switzerland and SEA Regional Manager of IMTE AG Ltd. with office in Malaysia.

Mr. Susta is also involved in Sepang 710MW CCGT project in Malaysia.