scholarly journals Development of a High Pressure Ratio Centrifugal Compressor for 300kW-Class Ceramic Gas Turbine

Author(s):  
T. Sakai ◽  
Y. Tohbe ◽  
T. Fujii ◽  
T. Tatsumi

Research and development of ceramic gas turbines (CGT), which is promoted by the Japanese Ministry of International Trade and Industry (MITI), was started in 1988. The target of the CGT project is development of a 300kW-class ceramic gas turbine with a 42 % thermal efficiency and a turbine inlet temperature (TIT) of 1350°C. Two types of CGT engines are developed in this project. One of the CGT engines, which is called CGT302, is a recuperated two-shaft gas turbine with a compressor, a gas-generator turbine, and a power turbine for cogeneration. In this paper, we describe the research and development of a compressor for the CGT302. Specification of this compressor is 0.89 kg/sec air flow rate and 8:1 pressure ratio. The intermediary target efficiency is 78% and the final target efficiency is 82%, which is the highest level in email centrifugal compressors like this one. We measured impeller inlet and exit flow distribution using three-hole yaw probes which were traversed from the shroud to the hub. Based on the measurement of the impeller exit flow, diffusers with a leading edge angle distribution adjusted to the inflow angle were designed and manufactured. Using this diffuser, we were able to attain a high efficiency (8:1 pressure ratio and 78% adiabatic efficiency).

Author(s):  
Matti Malkamäki ◽  
Ahti Jaatinen-Värri ◽  
Antti Uusitalo ◽  
Aki Grönman ◽  
Juha Honkatukia ◽  
...  

Decentralized electricity and heat production is a rising trend in small-scale industry. There is a tendency towards more distributed power generation. The decentralized power generation is also pushed forward by the policymakers. Reciprocating engines and gas turbines have an essential role in the global decentralized energy markets and improvements in their electrical efficiency have a substantial impact from the environmental and economic viewpoints. This paper introduces an intercooled and recuperated three stage, three-shaft gas turbine concept in 850 kW electric output range. The gas turbine is optimized for a realistic combination of the turbomachinery efficiencies, the turbine inlet temperature, the compressor specific speeds, the recuperation rate and the pressure ratio. The new gas turbine design is a natural development of the earlier two-spool gas turbine construction and it competes with the efficiencies achieved both with similar size reciprocating engines and large industrial gas turbines used in heat and power generation all over the world and manufactured in large production series. This paper presents a small-scale gas turbine process, which has a simulated electrical efficiency of 48% as well as thermal efficiency of 51% and can compete with reciprocating engines in terms of electrical efficiency at nominal and partial load conditions.


Author(s):  
Toshiaki Abe ◽  
Takashi Sugiura ◽  
Shuji Okunaga ◽  
Katsuhiro Nojima ◽  
Yasukata Tsutsui ◽  
...  

This paper presents an overview of a development project involving industrial cogeneration technology using 8,000-kW class hybrid gas turbines in which both metal and ceramics are used in parts subject to high temperatures in order to achieve high efficiency and low pollution. The development of hybrid gas turbines focuses mainly on the earlier commercialization of the turbine system. Stationary parts such as combustor liners, transition ducts, and first-stage turbine nozzles (stationary blades) are expected to be fabricated from ceramics. The project aims at developing material for these ceramic parts that will have a superior resistance to heat and oxidation. The project also aims at designing and prototyping a hybrid gas turbine system to analyze the operation in order to improve the performance. Furthermore, the prototyped hybrid gas turbine system will be tested for long-term operation (4,000 hours) to verify that the system can withstand commercialization. Studies will be conducted to ensure that the system’s soundness and reliability are sufficient for industrial cogeneration applications.


Author(s):  
Sepehr Sanaye ◽  
Salahadin Hosseini

A novel procedure for finding the optimum values of design parameters of industrial twin-shaft gas turbines at various ambient temperatures is presented here. This paper focuses on being off design due to various ambient temperatures. The gas turbine modeling is performed by applying compressor and turbine characteristic maps and using thermodynamic matching method. The gas turbine power output is selected as an objective function in optimization procedure with genetic algorithm. Design parameters are compressor inlet guide vane angle, turbine exit temperature, and power turbine inlet nozzle guide vane angle. The novel constrains in optimization are compressor surge margin and turbine blade life cycle. A trained neural network is used for life cycle estimation of high pressure (gas generator) turbine blades. Results for optimum values for nozzle guide vane/inlet guide vane (23°/27°–27°/6°) in ambient temperature range of 25–45 ℃ provided higher net power output (3–4.3%) and more secured compressor surge margin in comparison with that for gas turbines control by turbine exit temperature. Gas turbines thermal efficiency also increased from 0.09 to 0.34% (while the gas generator turbine first rotor blade creep life cycle was kept almost constant about 40,000 h). Meanwhile, the averaged values for turbine exit temperature/turbine inlet temperature changed from 831.2/1475 to 823/1471°K, respectively, which shows about 1% decrease in turbine exit temperature and 0.3% decrease in turbine inlet temperature.


Author(s):  
Raik C. Orbay ◽  
Magnus Genrup ◽  
Pontus Eriksson ◽  
Jens Klingmann

When low calorific value gases are fired, the performance and stability of gas turbines may deteriorate due to a large amount of inertballast and changes in working fluid properties. Since it is rather rare to have custom-built gas turbines for low lower heating value (LHV) operation, the engine will be forced to operate outside its design envelope. This, in turn, poses limitations to usable fuel choices. Typical restraints are decrease in Wobbe index and surge and flutter margins for turbomachinery. In this study, an advanced performance deck has been used to quantify the impact of firing low-LHV gases in a generic-type recuperated as well as unrecuperated gas turbine. A single-shaft gas turbine characterized by a compressor and an expander map is considered. Emphasis has been put on predicting the off-design behavior. The combustor is discussed and related to previous experiments that include investigation of flammability limits, Wobbe index, flame position, etc. The computations show that at constant turbine inlet temperature, the shaft power and the pressure ratio will increase; however, the surge margin will decrease. Possible design changes in the component level are also discussed. Aerodynamic issues (and necessary modifications) that can pose severe limitations on the gas turbine compressor and turbine sections are discussed. Typical methods for axial turbine capacity adjustment are presented and discussed.


1987 ◽  
Vol 109 (1) ◽  
pp. 1-7 ◽  
Author(s):  
I. G. Rice

This paper presents a heat balance method of evaluating various open-cycle gas turbines and heat recovery systems based on the first law of thermodynamics. A useful graphic solution is presented that can be readily applied to various gas turbine cogeneration configurations. An analysis of seven commercially available gas turbines is made showing the effect of pressure ratio, exhaust temperature, intercooling, regeneration, and turbine rotor inlet temperature in regard to power output, heat recovery, and overall cycle efficiency. The method presented can be readily programmed in a computer, for any given gaseous or liquid fuel, to yield accurate evaluations. An X–Y plotter can be utilized to present the results.


Author(s):  
Erio Benvenuti

This axial compressor design was primarily focused to increase the power rating of the current Nuovo Pignone PGT10 Heavy-Duty gas turbine by 10%. In addition, the new 11-stage design favourably compares with the existing 17-stage compressor in terms of simplicity and cost. By seating the flowpath and blade geometry, the new aerodynamic design can be applied to gas turbines with different power ratings as well. The reduction in the stage number was achieved primarily through the meridional flow-path redesign. The resulting higher blade peripheral speeds achieve larger stage pressure ratios without increasing the aerodynamic loadings. Wide chord blades keep the overall length unchanged thus assuring easy integration with other existing components. The compressor performance map was extensively checked over the speed range required for two-shaft gas turbines. The prototype unit was installed on a special PGT10 gas turbine setup, that permitted the control of pressure ratio independently from the turbine matching requirements. The flowpath instrumentation included strain-gages, dynamic pressure transducers and stator vane leading edge aerodynamic probes to determine individual stage characteristics. The general blading vibratory behavior was proved fully satisfactory. With minor adjustments to the variable stator settings the front stage aerodynamic matching was optimized and the design performance was achieved.


1974 ◽  
Author(s):  
V. V. Uvarov ◽  
V. S. Beknev ◽  
E. A. Manushin

There are two different approaches to develop the gas turbines for power. One can get some megawatts by simple cycle or by more complex cycle units. Both units require very different levels of turbine inlet temperature and pressure ratio for the same unit capacity. Both approaches are discussed. These two approaches lead to different size and efficiencies of gas turbine units for power. Some features of the designing problems of such units are discussed.


Author(s):  
Ryozo Tanaka ◽  
Testuo Tastumi ◽  
Yoshihiro Ichikawa ◽  
Koji Sanbonsugi

Based on the successful results of the Japanese national project for 300 kW ceramic gas turbine(CGT302) development (this project was finished in March 1999), the Ministry of International Trade and Industry (MITI) started “Research and Development on Practical Industrial Co-generation Technology” project in August 1999. The objective of this project is to encourage prompt industrial applications of co-generation technology that employs hybrid gas turbines (HGT; using both metal and ceramic parts in its high-temperature section) by confirming its soundness and reliability. The development activities are performed through material evaluation tests and long-term operation tests for the HGT of the medium size (8,000-kW class). It is expected that the development can realize low pollution and reducing the emission of CO2 with highly efficient use of energy. The HGT will be developed by applying ceramic components to an existing commercial 7,000-kW class gas turbine. The development targets are thermal efficiency of 34% or higher, output of 8,000-kW class, inlet temperature of 1250deg-C, and 4,000hrs of operation period for confirmation of reliability. The HGT for long-term evaluation tests and the test plant are under development. This paper gives the summary of last year’s developments in the HGT project.


Author(s):  
Isashi Takehara ◽  
Tetsuo Tatsumi ◽  
Yoshihiro Ichikawa

The Japanese Ceramic Gas Turbine (CGT) research and development program (FY1988–1998) as a part of the New Sunshine Project funded by the Ministry of International Trade and Industry (MITI) was completed in March 1999. Kawasaki Heavy Industries, Ltd. (KM) participated in this research program from the beginning and developed a twin-shaft CGT with a recuperator, designated as the “CGT302”. The purposes of this program were: 1) to achieve both a high efficiency and low pollutant emissions level using ceramic components, 2) to prove a multi-fuel capability to be used in co-generation systems, and 3) to demonstrate long-term operation. The targets of this program were: i) to achieve a thermal efficiency of over 42% at a turbine inlet temperature (TIT) of 1350°C, ii) to keep its emissions within the regulated value by the law, and iii) to demonstrate continuous operation for more than a thousand hours at 1200°C TIT. The CGT302 has successfully attained its targets. In March 1999 the CGT302 recorded 42.1% thermal efficiency, and 31.7 ppm NOx emissions (O2 = 16%) at 1350°C TIT. At this time it had also accumulated over two thousand hours operation at 1200°C. In this paper, we summarize the development of the CGT302.


Author(s):  
A. Okuto ◽  
T. Kimura ◽  
I. Takehara ◽  
T. Nakashima ◽  
Y. Ichikawa ◽  
...  

Research and development project of ceramic gas turbines (CGT) was started in 1988 promoted by the Ministry of International Trade and Industry (MITI) in Japan. The target of the CGT project is development of a 300kW-class ceramic gas turbine with a 42 % thermal efficiency and a turbine inlet temperature (TIT) of 1350°C. Three types of CGT engines are developed in this project. One of the CGT engines, which is called CGT302, is a recuperated two-shaft gas turbine for co-generation use. In this paper, we describe the research and development of a combustor for the CGT302. The project requires a combustor to exhaust lower pollutant emissions than the Japanese regulation level. In order to reduce NOx emissions and achieve high combustion efficiency, lean premixed combustion technology is adopted. Combustion rig tests were carried out using this combustor. In these tests we measured the combustor performance such as pollutant emissions, combustion efficiency, combustor inlet/outlet temperature, combustor inlet pressure and pressure loss through combustor. Of course air flow rate and fuel flow rate are controlled and measured, respectively. The targets for the combustor such as NOx emissions and combustion efficiency were accomplished with sufficient margin in these combustion rig tests. In addition, we report the results of the tests which were carried out to examine effects of inlet air pressure on NOx emissions here.


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