Demonstration of Model-Based, Off-Line Performance Analysis on a Gas Turbine Air Compressor

Author(s):  
Ashley P. Wiese ◽  
Matthew J. Blom ◽  
Michael J. Brear ◽  
Chris Manzie ◽  
Anthony Kitchener

This paper presents a model-based, off-line method for analyzing the performance of individual components in an operating gas turbine. This integrated model combines submodels of the combustor efficiency, the combustor pressure loss, the hot-end heat transfer, the turbine inlet temperature, and the turbine performance. As part of this, new physics-based models are proposed for both the combustor efficiency and the turbine. These new models accommodate operating points that feature the flame extending beyond the combustor and combustion occurring in the turbine. Systematic model reduction is undertaken using experimental data from a prototype, microgas turbine rig built by the group. This so called gas turbine air compressor (GTAC) prototype utilizes a single compressor to provide cycle air and a supply of compressed air as its sole output. The most general model results in sensible estimates of all system parameters, including those obtained from the new models that describe variations in both the combustor and turbine performance. As with other microgas turbines, heat losses are also found to be significant.

Author(s):  
Francesco Farina ◽  
Franco Donatini

A preliminary procedure has been developed to analyse the cooling of both nozzle and rotor blades in a gas turbine, evaluating the influence of the system on the performance of the machine. The developed method, which is based on a second law approach, defines the effects of the thermodynamic losses due to the forced convection air blade cooling on the performance of a typical heavy duty gas turbine in terms of lost exergy as function of the turbine inlet temperature.


Author(s):  
Ashley P. Wiese ◽  
Matthew J. Blom ◽  
Michael J. Brear ◽  
Chris Manzie ◽  
Anthony Kitchener

This paper presents a model based, off-line method for analysing the performance of individual components in an operating gas turbine. As with other studies, a least squares approach is employed. The component models are physics-based where possible. In its most general form, the method permits simultaneous inference of the combustor efficiency and stagnation pressure loss, the hot-end heat losses and associated heat transfer coefficients, the turbine inlet temperature and the turbine’s isentropic efficiency. As part of this, combustion of unburnt fuel within the turbine is modelled. The method is demonstrated on a so-called ‘Gas Turbine Air Compressor (GTAC)’ test rig built by the group, a micro-turbine whose compressor supplies air for both the cycle and external applications, but produces no shaft work. The method is also formulated for other gas turbines. The highest order models are tested first, and then the model order is progressively reduced to determine adequate component model complexity. Since the GTAC is a micro-gas turbine, heat losses are found to be significant. It is also shown that care must be taken to distinguish between variations in the performance of different components, since the performance of several components can have similar effects on the complete, operating device.


Author(s):  
Keisuke Makino ◽  
Ken-Ichi Mizuno ◽  
Toru Shimamori

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1,350 °C in accordance with the project goals, we developed two silicon nitride materials with further unproved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. In this paper, we report on the properties of these materials, and present the results of evaluations of these materials when they are actually used for CGT components such as first stage turbine blades and power turbine nozzles.


Author(s):  
Joshua A. Clough ◽  
Mark J. Lewis

The development of new reusable space launch vehicle concepts has lead to the need for more advanced engine cycles. Many two-stage vehicle concepts rely on advanced gas turbine engines that can propel the first stage of the launch vehicle from a runway up to Mach 5 or faster. One prospective engine for these vehicles is the Air Turborocket (ATR). The ATR is an innovative aircraft engine flowpath that is intended to extend the operating range of a conventional gas turbine engine. This is done by moving the turbine out of the core engine flow, alleviating the traditional limit on the turbine inlet temperature. This paper presents the analysis of an ATR engine for a reusable space launch vehicle and some of the practical problems that will be encountered in the development of this engine.


Author(s):  
K. Sarabchi ◽  
A. Ansari

Cogeneration is a simultaneous production of heat and electricity in a single plant using the same primary energy. Usage of a cogeneration system leads to fuel energy saving as well as air pollution reduction. A gas turbine cogeneration plant (GTCP) has found many applications in industries and institutions. Although fuel cost is usually reduced in a cogeneration system but the selection of a system for a given site optimally involves detailed thermodynamic and economical investigations. In this paper the performance of a GTCP was investigated and an approach was developed to determine the optimum size of the plant to meet the electricity and heat demands of a given site. A computer code, based on this approach, was developed and it can also be used to examine the effect of key parameters like pressure ratio, turbine inlet temperature, utilization period, and fuel cost on the economics of GTCP.


Author(s):  
Kozi Nishio ◽  
Junzo Fujioka ◽  
Tetsuo Tatsumi ◽  
Isashi Takehara

With the aim of achieving higher efficiency, lower pollutant emissions, and multi-fuel capability for small to medium-sized gas turbine engines for use in co-generation systems, a ceramic gas turbine (CGT) research and development program is being promoted by the Japanese Ministry of International Trade and Industry (MITI) as a part of its “New Sunshine Project”. Kawasaki Heavy Industries (KHI) is participating in this program and developing a regenerative two-shaft CGT (CGT302). In 1993, KHI conducted the first test run of an engine with full ceramic components. At present, the CGT302 achieves 28.8% thermal efficiency at a turbine inlet temperature (TIT) of 1117°C under ISO standard conditions and an actual TIT of 1250°C has been confirmed at the rated speed of the basic CGT. This paper consists of the current state of development of the CGT302 and how ceramic components are applied.


Author(s):  
Katsuyoshi Tada ◽  
Kei Inoue ◽  
Tomo Kawakami ◽  
Keijiro Saitoh ◽  
Satoshi Tanimura

Gas-turbine combined-cycle (GTCC) power generation is clean and efficient, and its demand will increase in the future from economic and social perspectives. Raising turbine inlet temperature is an effective way to increase combined cycle efficiency and contributes to global environmental conservation by reducing CO2 emissions and preventing global warming. However, increasing turbine inlet temperature can lead to the increase of NOx emissions, depletion of the ozone layer and generation of photochemical smog. To deal with this issue, MHPS (MITSUBISHI HITACHI POWER SYSTEMS) and MHI (MITSUBISHI HEAVY INDUSTRIES) have developed Dry Low NOx (DLN) combustion techniques for high temperature gas turbines. In addition, fuel flexibility is one of the most important features for DLN combustors to meet the requirement of the gas turbine market. MHPS and MHI have demonstrated DLN combustor fuel flexibility with natural gas (NG) fuels that have a large Wobbe Index variation, a Hydrogen-NG mixture, and crude oils.


Author(s):  
Nanahisa Sugiyama

A Performance Seeking Control (PSC) can realize the operations advantageous enough to accomplish the economy, safety, engine life, and environmental issues by reducing the control margin to the extremity together with selection of the control variables so that various kinds of parameters will be minimized or maximized. This paper describes the results obtained from the simulation study concerning the PSC aiming at the efficiency enhancement, power improvement, and longer engine life of a two-spool regenerative gas turbine engine having two control variables. By constructing the dynamic simulation of the engine, steady-state characteristics and dynamic characteristics are derived; then, a PSC system is designed and evaluated. It is concluded that the PSC for the gas turbine of this type can be realized by the turbine inlet temperature control.


Author(s):  
V. C. Tendon ◽  
A. Zabrodsky

Development and operation of larger size gas turbines have demonstrated that higher turbine inlet temperature can be sustained due to advancement in material and cooling technology. After a feasibility study it was determined that modern available technology can be applied to existing previous generation of machines. These programs are identified as “The Performance Upgrade of Gas Turbine”. Amongst the significant benefits that can be realized by retrofitting state of art parts in existing machines are higher power and more durable parts. This paper discusses various programs that are currently offered and implementation technique of upgrading the machines. A recent example is also presented. These unique programs are particularly attractive at the time of overall life consumption of the initial set of hot parts. At that point in an operating gas turbine it will be beneficial to retrofit the latest configuration parts to realize the performance improvements.


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