Gas Turbine Installation Research Articles

A choice of trailing edge diameter of gas turbine blades

A possibility of increasing the efficiency and profitability of gas-turbine installations by optimization of the geometry of trailing parts of the blades profiles is considered. This is done on the basis of actual data on characteristics of the blades of gas turbines manufactured by Western companies.

Energy Accumulating Material Application as an Alternate Fuel for Gas-turbine Installations

This article deals with the possibility of energy accumulative matters (EAM) usage as an alternative fuel for gas-turbine engines and plants. Ternary alloys of Si, Al and Fe are examined as industrial EAM. Combustion heat and adiabatic temperatures of EAM burning are estimated in superheated steam at variable oxidizer ratios. The composition of condensed combustion product is estimated at variable fractional composition of EAM.

Organization of Air Preparation for Gas-Turbine Power Units of Different Power Capacities

The experience gained at the Central Boiler-Turbine Institute Research and Production Association in the design and manufacture of air preparation systems for gas turbines is described. Some recent developments are used to illustrate the main principles and methods of constructing modern air preparation devices for gas-turbine power installations of different power capacities and for different climatic conditions.

Modeling and simulating combustion and generation of NO x

This paper deals with the modeling and simulation of combustion processes and generation of NO x in a combustion chamber and boiler, with supplementary combustion in a gas turbine installation. The fuel burned in the combustion chamber was rich gas with a chemical composition more complex than natural gas. Pitcoal was used in the regenerative boiler. From the resulting combustion products, 17 compounds were retained, including nitrogen and sulphur compounds. Using the developed model, the simulation resulted in excess air for a temperature imposed at the combustion chamber exhaust. These simulations made it possible to determine the concentrations of combustion compounds with a variation in excess combustion.

Preparation, Structure, and Properties of Ni<sub>3</sub>Al and NiAl Light Powder Alloys for Aerospace

New light super-heat-resistant powder Ni3Al and NiAl-based alloys (of the Ni-Al-Mo-B, Ni-Al-Fe-La, and Ni-Al-Y2O3 systems), as well as a new technology for preparing and processing them have been developed. The density of the alloys was 7.3-7.5 and ~6 g/cm 3, respectively. The Ni3Al sheets were used to prepare shields for combustion chambers in gas-turbine engines by roomtemperature deformation; the shields are intended for the long-term operation at 1100-1200°C and for the short-term use at 1300°C. The activated NiAl powders alloyed with Fe+La were used to produce sintered complex-shape articles, such as combustion stabilizers in a jet unit of combustion chamber of the gas-turbine installation, heat sources, etc. capable of operating at t≤1500°C under low mechanical stresses. At 1100, 1300, and 1500°C, the 100-h strength of the heat-resistant NiAl- (2-7.5) vol. % Y2O3 alloys subjected to directional recrystallization is 70, 35 and ≥10 MPa, respectively. The vanes, in which the length of recrystallized grain is smaller than the vane length by a factor of 1.5-2, were manufactured from these alloys.

Calculation study of water injection on compressor characteristics of a GT-009 gas-turbine installation

Results of a calculation study of motion and evaporation of water in the compressor flow path of a GT-009 gas-turbine installation are presented. The effects of water injection on the main characteristics of the compressor operation are analyzed.

Technical and economical feasibility of the Rankine compression gas turbine (RCG)

The Rankine compression gas turbine (RCG) is a new type of combined cycle, i.e. combined steam and gas turbine installation, that returns all shaft power on one free power turbine. The novelty of the RCG is that the steam turbine drives the compressor of the gas turbine cycle. This way, the turbine of the gas turbine acts as a free power turbine. With its free power turbine the possible field of application of the RCG is mechanical drives. The RCG can be designed with components that can all be referred to as existing technology, which makes the RCG robust and technologically feasible. Thermodynamic calculations show that a thermal efficiency of about 40% is realistic. This is higher than simple cycle gas turbines, and equal to gas turbines with a recuperator. The calculations also show that the specific power of an RCG is up to twice as high than that of both simple cycle and recuperative cycle gas turbines. Finally, economical assessments show that the extra investments of an RCG compared to a simple cycle have an expected payback time of 2–4 years. This makes the RCG economically appealing, but further study is necessary to obtain more exact figures on the economical feasibility.

Low-frequency noise and air vibration generated by a simple cycle gas turbine installation

Standard noise regulations, measurement techniques, and acoustic treatments can fail to address energy emitted by certain problem gas turbine installations in the form of low-frequency noise and air vibrations. Survey and treatment of the entire acoustic environment is necessary to diagnose and solve these annoyance problems. The presence of ground-borne vibrations, infrasound, and noise in the lower octave bands complicates environmental noise assessment and limits mitigation options. Variability in the perception, effects, and annoyance level of low-frequency noise and air vibrations prevents this relatively common problem from being well understood by industry. Particular attention must be paid to propagation paths when the dynamic range of air-borne and ground-borne vibrations overlaps. This paper is the case study of a 2002 analysis, by ATCO Noise Management, of an installation consisting of 3–120 MW combustion generator turbines causing such low-frequency noise and air vibrations.

Comparison of the efficiency of the variants of a primary gas turbine supplementing a coal-fired power plant

Thermodynamic effects of four variants of the installation of a primary gas turbine supplementing a coal-fired power plant have been determined. The variants differ in the utilization mode of the heat recovery boiler of the gas turbine, which may be used to preheat the feed water of the steam power plant, but also for a secondary superheating of the steam. The introduction of an additional gas turbine expanding the working fluid down to a pressure lower than the ambient one with an additional compressor installed after the heat recovery boiler has been considered too. The reduction of exergy losses in the heat recovery boiler has been accepted as the main purpose of changing the scheme of the system. The new variants have been compared by means of the incremental energy efficiency of the gas turbine, characterizing the utilization degree of natural gas in the complex system.

Measurements of the transient velocity field in a strongly curved diffusing bend with periodic inflow unsteadiness

This study examined the effects of periodic inflow unsteadiness on the flow development through fishtail-shaped diffusers utilized on small gas turbine engines. The periodic unsteadiness is due to the distortion of the flow in the peripheral direction at the exit of the centrifugal compressor impeller, caused by the jet-wake type of flow discharging from each impeller passage. Measurements of the transient velocity field were performed throughout the diffuser using a miniature 4-wire probe, at frequencies of inflow unsteadiness corresponding to design and off-design operating conditions in gas turbine installations. At the low end of the tested inflow unsteadiness frequencies, significant effects of inflow unsteadiness were observed on the time-averaged flow distortion throughout the diffuser. At these frequencies, the time variation of flow distortion was found to remain at comparable magnitudes throughout the diffuser.

The study of capacity enhancement of the Chabahar gas turbine installation using an absorption chiller

The strong influence of climate conditions on gas turbine behavior it is well known. The output of gas turbines falls to a value that is less than the rated output under high temperature conditions that often occur during the summer season. Cooling the turbine inlet air can increase output power substantially. This is because cooled air is denser, giving the turbine a higher mass flow rate and resulting in increased turbine output and efficiency. This paper presents an overview of an intake air-cooling system that uses a steam absorption chiller and an air cooler to address the above problem in the Chabahar power plant. By using this technique the output power will increase by 11.3%. The economical studies have shown the internal rate of return will be 23.4%. The cost of electricity is calculated to be 1.45 Cents/kW h which is less than the current price of electricity in Iran. The payback period is estimated to be around 4.2 years.

Gas turbine installations with divided expansion : Cårdu, M. and Baica, M. Energy Conversion and Management, 2002, 43, (13), 1747–1756

The strategies implemented at Eli Lilly and Company to address European Medicines Agency and US Food and Drug Administration requirements governing the control of genotoxic impurities (GTIs) are presented. These strategies were developed to provide understanding with regard to the risk and potential liabilities that could be associated with developmental and marketed compounds. The strategies systematize the assessment of impurities for genotoxic potential, addressing both actual and potential impurities. Timing of activities is designed to minimize impact to development timelines while building a data package sufficient to either discharge the risk of potential GTI formation or support the implementation of a specification necessary for long-term control. This article presents the background associated with GTI control, the types of impurities that should be assessed, and the actions to be taken when an impurity is found to be genotoxic. A systematic approach to define potential degradation products derived from stress-testing studies is outlined with a proposal to perform a genotoxic risk assessment on these impurities. Finally, an Arrhenius-based strategy is proposed for a rapid assessment of the likelihood of potential degradation impurities to form in the commercial drug product formulation. Importantly, this article makes a proposal for discharging the risk of a potential GTI with supporting data.

Analytical solutions and typical characteristics of part-load performances of single shaft gas turbine and its cogeneration : Zhang, N. and Cai, R. Energy Conversion and Management, 2002, 43, (9–12), 1323–1337

Explicit analytical solutions of part-load performances of constant rotating speed single shaft gas turbine and its cogeneration are derived based on analytical typical component performances. Their typical partload operation regularities are summarized as well. For the gas turbine installation,it is found out that the relative gas turbine efficiency variation can almost be summarized as a single curve that is consistent with the practical data. The part-load performances of gas turbine cogeneration are investigated for the industrial process heat supply with saturated steam. It is found out that the variations of the steam flow rate and work/heat ratio are almost not influenced by the gas turbine design values,and it is worth emphasizing that the approach temperature difference in a heat recovery steam generator is likely to be negative in low load condition with high steam parameter and low ambient temperature.@ 2002 Elsevier Science Ltd. All rights reserved.

ProSteam—A Structured Approach To Steam System Improvement

ABSTRACT Optimal operation of site utility systems is becoming an increasingly important part of any successful business strategy as environmental, legislative, and commercial pressures grow. A reliable steam model allows a clear understanding of the system and of any operational constraints. It can also be used to determine the true cost of improvement projects, relating any changes in steam demand back to purchased utilities (fuel, power, and make-up water) at the site boundary. Example projects could include improved insulation, better condensate return, increased process integration, new steam turbines, or even the installation of gas-turbine based cogeneration. This approach allows sites to develop a staged implementation plan for both operational and capital investment projects in the utility system. Steam system models can be taken one step further and linked to the site DCS data to provide real-time balances and improve the operation of the system, providing an inexpensive but very effective optimizer. Such a model ensures that the steam system is set in the optimum manner to react to current utility demands, emissions regulations, equipment availability, fuel and power costs, etc. This optimization approach typically reduces day-to-day utility system operating costs by between 1 percent and 5 percent at no capital cost.

Identification of the Modal Parameters of a Flexibly Supported Rigid Casing

Satisfactory means for evaluating the vibration behavior of gas turbine installations where it is impractical to obtain a satisfactory model of the support structure and where it has natural frequencies in the operating range are not yet available. This paper investigates the feasibility of identifying the modal parameters of a flexibly supported rigid casing to predict the unbalance response of the contained rotor. Assumed known are the location of the principal axes of inertia of the casing. Numerical experiments demonstrate that the identification procedure works well even with a measurement accuracy of only two significant digits. Thus, the procedure is expected to be practically feasible, though no sensitivity studies have yet been carried out to determine the limitations imposed by the assumed location of the principal axes.

Compact gas turbine installation

Compact gas turbine installation

Gas turbine installations with divided expansion

In this paper, the authors describe a new type of gas turbine installation (GTI), where the working fluid expansion is successively performed in two segments of the gas turbine (GT) (divided expansion). Between the two segments of the GT is disposed a heat recuperator which uses the heat of the working fluid leaving the first segment of the GT in order to heat the compressed air before its entrance in the combustion chamber (chambers). The result of the divided expansion of the working fluid and the presence of the heat recuperator between the two segments of the GT consists in an increase of the installation thermal efficiency in comparison with the thermal efficiency of the existing GTIs without divided expansion in similar operating conditions.

Analytical solutions and typical characteristics of part-load performances of single shaft gas turbine and its cogeneration

Explicit analytical solutions of part-load performances of constant rotating speed single shaft gas turbine and its cogeneration are derived based on analytical typical component performances. Their typical part-load operation regularities are summarized as well. For the gas turbine installation, it is found out that the relative gas turbine efficiency variation can almost be summarized as a single curve that is consistent with the practical data. The part-load performances of gas turbine cogeneration are investigated for the industrial process heat supply with saturated steam. It is found out that the variations of the steam flow rate and work/heat ratio are almost not influenced by the gas turbine design values, and it is worth emphasizing that the approach temperature difference in a heat recovery steam generator is likely to be negative in low load condition with high steam parameter and low ambient temperature.

Positive feedback stabilization of centrifugal compressor surge

Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to stabilize the system around this point. As a result, only nonnegative control values are allowed, which complicates the controller design considerably. A novel positive feedback controller is proposed which is based on the pole placement technique. This controller has been successfully applied to a laboratory-scale gas turbine installation. Initial experiments show that the surge point mass flow can be reduced by at least 7%. Using this efficient control strategy, stable operation in the desired operating point is maintained with small average control valve mass flow.

Gas turbine installation with total water injection in the combustion chamber

In this paper, the authors present the results of their thermodynamic analysis, regarding gas turbine installations (GTIs) with total water injection in the combustion chamber (CC). Among existing GTIs, the majority are without water or steam injection in the working fluid, while some of them employ partial water/steam injection (GTIWI). The technical solution proposed by the authors, with total water injection (GTITWI), is designed to realize the desired temperature in the CC by means of the injected water exclusively. The introduced air flow is only the quantity strictly needed to produce combustion. As a result, for many cases, we have higher values for the thermal efficiency in a GTITWI compared with the GTIs without water/steam injection. Consequently, from this point of view, GTIWI are situated between GTI and GTITWI. Also, like for all GTIWI, for GTITWI too, using water injection results in much lower values for NO x emissions.