Eiji Akita

The Air Injection Power Augmentation Technology Provides Additional Significant Operational Benefits

The Air Injection (AI) Power Augmentation technology (HAI for humid Air injection and DAI for dry air injection) has primary benefits of increasing power of combustion turbine/combined cycle (CT/CC) power plants by 15–30% at a fraction of the new plant cost with coincidental significant heat rate reductions (10–15%) and NOx emissions reductions (for diffusion type combustors up to 60%) (See References 1, 2, 3): Figure 1A is a simplified heat and mass balance for the PG7241 (FA) combustion turbine with HAI. The auxiliary compressor supplies the additional airflow that is mixed with the steam produced by the HRSG and injected upstream of combustors. Figure 1B presents the heat and mass balance for the PG7142 CT based combined cycle power plant with HAI. It is similar to that presented on Figure 1A except that the humid air is created by mixing of steam, extracted from the steam turbine, with the supplementary airflow from the auxiliary compressor. The maximum acceptable injection rates are evaluated with proper margins by a number of factors established by OEMs: the compressor surge limitations, maximum torque, the generator capacities, maximum moisture levels upstream of combustors, etc.Copyright

The Operating Experience of the Next Generation M501G/M701G Gas Turbine

The combined cycle power plant is recognized as one of the best thermal power plant for its high efficiency and cleanliness. As the main component of the combined cycle power plant, the gas turbine is the key for improvement of the combined cycle power plant.The next generation G class gas turbine, with turbine inlet gas temperature in 1,500°C range has been developed by Mitsubishi Heavy Industries, Ltd. (MHI). Many advanced technologies; a high efficiency compressor, a steam cooled low NOx combustor, a high temperature and high efficiency turbine, etc., are employed to achieve high combined cycle performance. Actually, MHI has been accumulating the operating experiences of M501G (60Hz machine) a combined cycle verification plant in MHI Takasago, Japan, and achieving the high performance and reliability. Also, M701G (50Hz machine) has been accumulating the operating experience in Higashi Niigata Thermal Power Station of Tohoku Electric Power Co., Inc. in Japan.This paper describes the technical features of M501G/M701G, and up-to-date operating status of the combined cycle power plant in MHI Takasago, Japan.© 2001 ASME

Development and Testing of the 13MW Class Heavy Duty Gas Turbine MF-111

A new 13 MW class heavy duty gas turbine “MF-111” with the combustor outlet temperature of 1250°C (1523 K) was developed and tested.The thermal efficiency of MF-111 is designed to be 32% for simple-cycle and 45% in combined-cycle operation.MF-111 has single-shaft configuration, 15-stage axial flow compressor, 8 cannular type combustors and 3-stage axial flow turbine.Advanced cooling technology was incorporated for the turbine and the combustor design to be capable of higher combustor outlet temperature.The prototype was shoptested at full load in April, 1986. The performance and the metal temperatures of hot parts were confirmed to well satisfy the design goal. The first machine of MF-111 started the commercial operation from August, 1986 and has logged satisfactory operations.© 1987 ASME

501F/M701F Gas Turbine Uprating

The share of the gas turbine combined cycle plants tends to increase rapidly in the world of power generation. Under the circumstances, MHI is developing the several kinds of gas turbine to meet each customer’s needs.The ‘F’ series’ engine, which has a firing temperature of 1350–1400 degree C, is predominant in the current market, and the reliability improvement is constantly performed. As a result, the operational hours of 50,000, and the combined cycle efficiency of 55–57% (LHV) is achieved for F-series combined cycle.During the operating experience, any events occurred in field operation is solved. Also, countermeasure was implemented on every machine. Furthermore, robust design improvement is introduced, and commercial operation of the design achieved higher reliability and availability.In this paper, the operating experiences, design improvements and the F series gas turbine uprating program are introduced.© 2001 ASME

Development of the Next Generation 1500°C Class Advanced Gas Turbine for 50Hz Utilities

The 701G1 50Hz Combustion Turbine continues a long line of large heavy-duty single-shaft combustion turbines by combining the proven efficient and reliable concepts of the 501F and 701F. The output of the 701G1 is 255MW with combined cycle net efficiency of over 57%. A pan of component development was conducted under the joint development program with Tohoku Electric Power Co., Inc. and a part of the design work was carried out under the cooperation with Westinghouse Electric Corporation in the U.S.A. and Fiat Avio in Italy.This gas turbine is going to be installed to “Higashi Niigata Power Plants NO.4” of Tohoku Electric Power Co., Inc. in Japan. This plant will begin commercial operation in 1999.This paper describes some design results and new technologies in designing and developing this next generation 1500°C class advanced gas turbine.Copyright

Uprated 501F Gas Turbine, 501FA

This paper introduces the engineering approach taken in developing the 501FA gas turbine, which is an uprated version of the existing 501F 150MW class gas turbine. The concepts and procedures which were utilized to uprate this gas turbine are also presented. To achieve better performance, new techniques were incorporated which reflected test results and operating experience. No advanced technologies were introduced. Instead, well experienced techniques are adopted so as not to deteriorate reliability. Improvement of the performance was mainly achieved mainly due to the reduction of cooling air. Tip clearances were also optimized based on shop test and field results.Copyright