Status of the Development of the CGT301, a 300 KW Class Ceramic Gas Turbine

Abstract

The CGT301 ceramic gas turbine is being developed under a contract from NEDO as a part of the New Sunshine Program of MTTI to improve the performance of gas turbines for cogeneration through the replacement of hot section components with ceramic parts. The project is conducted in three phases. The project currently in Phase 2 focuses on the development of the “primary type” ceramic gas turbine (turbine inlet temperature: 1,200°C). CGT301 is a recuperated, single-shaft, ceramic gas turbine. The turbine is a two-stage axial flow type. The major effort has been on the development of the turbine which consists of metallic disks and inserted ceramic blades (“hybrid rotor”). Prior to engine tests, component tests were performed on the hybrid rotor to prove the validity of the design concepts and their mechanical integrity. The engine equipped with all ceramic components except the second stage turbine blades was tested and evaluated. The engine was operated successfully for a total of 23 hours without failure at the rated engine speed of 56,000 rpm with the turbine inlet temperature of 1,200 °C. Further, the engine equipped with all ceramic components was successfully tested for one hour under the same conditions. Engine testing of the “primary type” ceramic gas turbine is continuing to improve the performance and the reliability of the system for the purpose of moving forward to the development of the “pilot” ceramic gas turbine (turbine inlet temperature: 1,350 °C) as the final target of this project. This paper summarizes the progress in the development of the CGT301 with the emphasis on the test results of the hybrid rotor.

Development of the Ceramic Gas Turbine Engine System (CGT301)

“…The test result by the turbine performance test rig in Primary type COT is shown in Fig.3 The seal damper made of ceramic fiber was developed to prevent gas leakage between the blade platform and the disk spot.[Ref. 5,6] Further the turbine disk was modified for decreasing gas leakage. [Ref.6] The rim of the disk was shaped -> to minimize the clearance with the blade platform.…”

“…In hot spin testing the hybrid rotor was successfully tested at TIT of 1,200*C. Then the engine equipped with the hybrid rotor was operated successfully in Phase2. [Ref.2,3,5,6) By these technology development of the hybrid rotor, the development of the turbine has been conducted to increase TIT and to improve the performance and the reliability in The blade height is 10% higher than that of the Primary type CGT(Type-A) to decrease the clearance loss.…”

“…It has been developed by Ishikawajima-Harima Heavy Industries Co., Ltd in collaboration with NGK Insulators, Ltd., and NGK Spark Plug Co., Ltd. [Ref. [1][2][3][4][5][6] The schedule of the project is shown in Table 1. The project was conducted in three phases.…”

“…The engine equipped with all ceramic components was operated successfully and the target performance was achieved in Phase2.[Ref. 3,5] The development of Pilot CGT has been conducted to attain the target of Phase3. BASIC DESIGN CONCEPT OF CGT301 Fig.1 shows the concept figure of CGT301.…”

Current Status of the CGT301, Ceramic Gas Turbine

“…The seal damper which was originally developed as a friction damper for blade vibration was adopted to reduce the leakage. [3] The seal damper made of carbon fiber weave was formed to fit the curved surface of the blade platform and inserted between blades. Its weight is about less than 4% of the blade to minimize the additional centrifugal force loaded on the blade neck.…”