Ceramic Recuperator and Turbine: The Key to Achieving a 40 Percent Efficient Microturbine

Author(s):  
Colin F. McDonald ◽  
Colin Rodgers

Based on the use of state-of-the-art component technologies and the use of existing metallic materials, achieving an electrical efficiency anywhere near 40 percent in low pressure ratio recuperated microturbines is proving elusive. Current microturbines, rated at say 100 kW, operate with efficiencies approaching 30 percent. Advancing this to an upper level of about 35 percent is projected based on the ability to operate at turbine inlet temperatures greater than 1100C, and the utilization of a higher cost superalloy recuperator. This paper puts into perspective the challenge of trying to achieve 40 percent efficiency for small recuperated turbogenerator designs with radial flow components; the major constraints being associated with stress limitations in both the turbine and recuperator. Various publications (issued by both industry and the Government) often mention an efficiency goal of 40 percent for small gas turbines of this configuration, however, it needs to be recognized that the means to achieve this are beyond current high temperature metallic component capabilities. To achieve this “goal” necessitates increasing the operating temperature of the turbine and recuperator above 1100C and 800C respectively. Such advancements are projected to be technically and cost-effectively achievable by utilizing ceramic components, which with a dedicated development program, could perhaps become a reality in less than a decade to meet both future distributed power generation needs and defense applications, and be in concert with ever-demanding conservation goals and reduced emissions.

Author(s):  
Oscar Jimenez ◽  
Hamid Bagheri ◽  
John McClain ◽  
Ken Ridler ◽  
Tibor Bornemisza

The Ceramic Stationary Gas Turbine (CSGT) Development Program was performed under the sponsorship of the United States Department of Energy (DOE), Office of Industrial Technologies (OIT). The goal was to improve the performance (fuel efficiency, output power, and exhaust emissions) of stationary gas turbines in cogeneration through the selective replacement of hot section metallic components with ceramic components. The team was headed by Solar Turbines Incorporated and supported by ceramic component suppliers and national research institutes. The team performed a detailed engine and component design, fabrication, and field-testing of ceramic components. This program culminated in an engine test at 1121°C (2050°F) TRIT. This was a major challenge in that the engine ran with a continuous fiber reinforced ceramic composite liner (CFCC) and with silicon nitride (Si3N4) stage one ceramic blades and nozzles. The design and testing of all three components will be discussed in this paper, with emphasis on the ceramic nozzles. Another test that will be discussed in this paper is a heavily instrumented engine test that took place prior to the test mentioned above. This instrumented engine test was performed in order to better understand the temperature effects between the ceramic and metallic component interfaces. The results from this were then used to correlate the analytical model with test data. This led to additional design changes to the outer and inner shroud ceramic / metallic interfaces, as well as ceramic nozzles, fabricated from Kyocera SN 282 silicon nitride material. These nozzle changes were then engine tested successfully for a total of 100 hours at full load [1010°C (1850°F) TRIT and 100% speed]. During the engine test, the firing temperature was increased to 1121°C (2050°F) TRIT for an adequate duration to ensure meaningful performance data were gathered.


Author(s):  
Satoshi Hada ◽  
Masanori Yuri ◽  
Junichiro Masada ◽  
Eisaku Ito ◽  
Keizo Tsukagoshi

MHI recently developed a 1600°C class J-type gas turbine, utilizing some of the technologies developed in the National Project to promote the development of component technology for the next generation 1700°C class gas turbine. This new frame is expected to achieve higher combined cycle efficiency and will contribute to reduce CO2 emissions. The target combined cycle efficiency of the J type gas turbine will be above 61.5% (gross, ISO standard condition, LHV) and the 1on1 combined cycle output will reach 460MW for 60Hz engine and 670MW for 50Hz engine. This new engine incorporates: 1) A high pressure ratio compressor based on the advanced M501H compressor, which was verified during the M501H development in 1999 and 2001. 2) Steam cooled combustor, which has accumulated extensive experience in the MHI G engine (> 1,356,000 actual operating hours). 3) State-of-art turbine designs developed through the 1700°C gas turbine component technology development program in Japanese National Project for high temperature components. This paper discusses the technical features and the updated status of the J-type gas turbine, especially the operating condition of the J-type gas turbine in the MHI demonstration plant, T-Point. The trial operation of the first M501J gas turbine was started at T-point in February 2011 on schedule, and major milestones of the trial operation have been met. After the trial operation, the first commercial operation has taken place as scheduled under a predominantly Daily-Start-and-Stop (DSS) mode. Afterward, MHI performed the major inspection in October 2011 in order to check the mechanical condition, and confirmed that the hot parts and other parts were in sound condition.


Author(s):  
Jeffrey R. Price ◽  
Oscar Jimenez ◽  
Les Faulder ◽  
Bryan Edwards ◽  
Vijay Parthasarathy

A program is being performed under the sponsorship of the United States Department of Energy, Office of Industrial Technologies, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of metallic hot section components with ceramic parts. The program focuses on design, fabrication, and testing of ceramic components, generating a materials properties data base, and applying life prediction and nondestructive evaluation (NDE). The development program is being performed by a team led by Solar Turbines Incorporated, and which includes suppliers of ceramic components, U.S. research laboratories and an industrial cogeneration end user. The Solar Centaur 50S engine was selected for the development program. The program goals included an increase in the turbine rotor inlet temperature (TRIT) from 1010°C (1850°F) to 1121°C (2050°F), accompanied by increases in thermal efficiency and output power. The performance improvements are attributable to the increase in TRIT and the reduction in cooling air requirements for the ceramic parts. The ceramic liners are also expected to lower the emissions of NOx and CO. Under the program uncooled ceramic blades and nozzles have been inserted for currently cooled metal components in the first stage of the gas producer turbine. The louvre-cooled metal combustor liners have been replaced with uncooled continuous-fiber reinforced ceramic composite (CFCC) liners. Modifications have been made to the engine hot section to accommodate the ceramic parts. To-date all first generation designs have been completed. Ceramic components have been fabricated, and are being tested in rigs and in the Centaur 50S engine. Field testing at an industrial co-generation site was started in May, 1997. This paper will provide an update of the development work and details of engine testing of ceramic components under the program.


Author(s):  
Michael J. Vick ◽  
Andrew Heyes ◽  
Keith Pullen

A three-kilowatt turboshaft engine with a ceramic recuperator and turbine has been designed for small unmanned air vehicle (UAV) propulsion and portable power generation. Compared with internal combustion (IC) engines, gas turbines offer superior reliability, engine life, noise and vibration characteristics, and compatibility with military fuels. However, the efficiency of miniature gas turbines must be improved substantially, without severely compromising weight and cost, if they are to compete effectively with small IC engines for long-endurance UAV propulsion. This paper presents a design overview and supporting analytical results for an engine that could meet this goal. The system architecture was chosen to accommodate the limitations of mature, cost-effective ceramic materials: silicon nitride for the turbine rotors, and toughened mullite for the heat exchanger and turbine stators. An engine with a cycle pressure ratio below 2:1, a multistage turbine, and a highly effective recuperator is shown to have numerous advantages in this context. A key benefit is a very low water-vapor-induced surface recession rate for silicon nitride, due to an extremely low partial pressure of water in the combustion products. Others include reduced sensitivity to internal flaws, creep, and foreign object damage; an output shaft speed low enough for grease-lubricated bearings; and the potential viability of a novel premixed heat-recirculating combustor.


1999 ◽  
Vol 121 (4) ◽  
pp. 586-592 ◽  
Author(s):  
J. R. Price ◽  
O. Jimenez ◽  
L. Faulder ◽  
B. Edwards ◽  
V. Parthasarathy

A program is being performed under the sponsorship of the United States Department of Energy, Office of Industrial Technologies, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of metallic hot section components with ceramic parts. The program focuses on design, fabrication, and testing of ceramic components, generating a materials properties data base, and applying life prediction and nondestructive evaluation (NDE). The development program is being performed by a team led by Solar Turbines Incorporated, and which includes suppliers of ceramic components, U.S. research laboratories, and an industrial cogeneration end user. The Solar Centaur 50S engine was selected for the development program. The program goals included an increase in the turbine rotor inlet temperature (TRIT) from 1010°C (1850°F) to 1121°C (2050°F), accompanied by increases in thermal efficiency and output power. The performance improvements are attributable to the increase in TRIT and the reduction in cooling air requirements for the ceramic parts. The ceramic liners are also expected to lower the emissions of NOx and CO. Under the program uncooled ceramic blades and nozzles have been inserted for currently cooled metal components in the first stage of the gas producer turbine. The louvre-cooled metal combustor liners have been replaced with uncooled continuous-fiber reinforced ceramic composite (CFCC) liners. Modifications have been made to the engine hot section to accommodate the ceramic parts. To date, all first generation designs have been completed. Ceramic components have been fabricated, and are being tested in rigs and in the Centaur 50S engine. Field testing at an industrial co-generation site was started in May, 1997. This paper will provide an update of the development work and details of engine testing of ceramic components under the program.


Author(s):  
Michael J. Vick ◽  
Andrew Heyes ◽  
Keith Pullen

A three kilowatt turboshaft engine with a ceramic recuperator and turbine has been designed for small unmanned air vehicle (UAV) propulsion and portable power generation. Compared with internal combustion (IC) engines, gas turbines offer superior reliability, engine life, noise and vibration characteristics, and compatibility with military fuels. However, the efficiency of miniature gas turbines must be improved substantially, without severely compromising weight and cost, if they are to compete effectively with small IC engines for long-endurance UAV propulsion. This paper presents a design overview and supporting analytical results for an engine that could meet this goal. The system architecture was chosen to accommodate the limitations of mature, cost-effective ceramic materials: silicon nitride for the turbine rotors and toughened mullite for the heat exchanger and turbine stators. An engine with a cycle pressure ratio below 2:1, a multistage turbine, and a highly effective recuperator is shown to have numerous advantages in this context. A key benefit is a very low water vapor-induced surface recession rate for silicon nitride, due to an extremely low partial pressure of water in the combustion products. Others include reduced sensitivity to internal flaws, creep, and foreign object damage; an output shaft speed low enough for grease-lubricated bearings; and the potential viability of a novel premixed heat-recirculating combustor.


Jurnal Niara ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 29-34
Author(s):  
Neneng Salmiah ◽  
Fahmi Oemar ◽  
Reni Farwitawati

The study aimed at conducting an analysis towards the operation of Athlete Homestead for the National Sports Week in 2012 belonging to Riau Province. Regarding the Finance Operation System in the form of Sub-district Development Program-Regional Public Service Agency (PPK BLUD), the researcher designed the Accounting System for the Regional Public Service Agency of the Rental Flats and Sports Venue. The data analysis in this study used the descriptive qualitative method by describing the accounting system design for the operation of Rental Flats and Sports Venue through the Sub-district Development Program-Regional Public Service Agency (PPK BLUD) with the procedure comprising: designing the rent system and procedure of the Rental Flats and Sports Venue, designing the system of cash management from the rent income, implementing focused-group discussion with the related parties and the government, working on the policy improvement draft for the operation of the Rental Flats and Sports Venue belonging to Riau Province.Based on the result of the study and discussion, it can be concluded that in order to improve the effectiveness of the service and operation of Rental Flats and Sports Venue with sound business practice, it is necessary to implement the Finance Operation System in the form of Sub-district Development Program-Regional Public Service Agency (PPK BLUD). The design system of the Sub-district Development Program-Regional Public Service Agency (PPK BLUD) comprising the organization chart, the transaction proof document, and the financial management procedure


2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis

When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.


2021 ◽  
pp. 009614422198997
Author(s):  
Marianna Charitonidou

The article presents the reasons for which the issue of providing housing to low-income citizens has been a real challenge in Addis Ababa during the recent years and will continue to be, given that its population is growing extremely fast. It examines the tensions between the universal aspirations and the local realities in the case of some of Ethiopia’s most ambitious mass pro-poor housing schemes, such as the “Addis Ababa Grand Housing Program” (AAGHP), which was launched in 2004 and was integrated in the “Integrated Housing Development Program” (IHDP) in 2006. The article argues that the quotidian practices of communities and their socio-economic and cultural characteristics are related to the spatial attributes of co-housing practices. Drawing upon the idea that there is a mutual correspondence between social and spatial structures, it places particular emphasis on the analysis of the IHDP and aims to show that to shape strategies that take into account the social and cultural aspects of daily life of the poor citizens of Addis Ababa, it is pivotal to invite them to take part in the decision-making processes regarding their resettlement. Departing from the fact that a large percentage of the housing supply in Addis Ababa consists of informal unplanned housing, the article also compares the commoning practices in kebele houses and condominium units. The former refers to the legal informal housing units owned by the government and rented to their dwellers, whereas the latter concerns the housing blocks built in the framework of the IHDP for the resettlement of the kebele dwellers. The article analyzes these processes of resettlement, shedding light of the fact that kebele houses were located at the inner city, whereas the condominiums are located in the suburbs. Despite the fact that the living conditions in the condominium units are of a much higher quality than those in the kebele houses, their design underestimated or even neglected the role of the commoning practices. The article highlights the advantages of commoning practices in architecture and urban planning, and how the implementation of participation-oriented solutions can respond to the difficulties of providing housing. It argues that understanding the significance of the endeavors that take into account the opinions of dwellers during the phase of decision-making goes hand in hand with considering commoning practices as a source of architecture and urban planning frameworks for low-cost housing in this specific context. The key argument of the article is that urban planning and architecture solutions in Addis Ababa should be based on the principles of the so-called “negotiated planning” approach, which implies a close analysis of the interconnections between planning, infrastructure, and land.


Author(s):  
M. F. Bardon ◽  
J. A. C. Fortin

This paper examines the possibility of injecting methanol into the compressor of a gas turbine, then dissociating it to carbon monoxide and hydrogen so as to cool the air and reduce the work of compression, while simultaneously increasing the fuel’s heating value. A theoretical analysis shows that there is a net reduction in compressor work resulting from this dissociative intercooling effect. Furthermore, by means of a computer cycle model, the effects of dissociation on efficiency and work per unit mass of airflow are predicted for both regenerated and unregenerated gas turbines. The effect on optimum pressure ratio is examined and practical difficulties likely to be encountered with such a system are discussed.


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