Research of characteristics of the flow part of an aerothermopressor for gas turbine intercooling air

Author(s):  
Dmytro Konovalov ◽  
Mykola Radchenko ◽  
Halina Kobalava ◽  
Andrii Radchenko ◽  
Roman Radchenko ◽  
...  

Complex gas turbine schemes with air intercooling are usually used to bring the compression process of working fluid in compressor closer to isothermal one. A promising way to realize it is to use an aerothermopressor. The aerothermopressor is a two-phase jet apparatus, in which the highly dispersed liquid (water) is injected into the superheated gas (air) stream accelerated to the speed closed to the sound speed value (Mach number from 0.8 to 0.9). The air pressure at the aerothermopressor outlet (after diffuser) is higher than at the inlet due to instantaneous evaporation of highly dispersed liquid practically without friction losses in mixing chamber and with an increase in pressure of the mixed homogenous flow. The liquid evaporation is conducted by removing the heat from the air flow. In the course of the experimental research, the operation of the aerothermopressor for gas turbine intercooling air was simulated and its characteristics (hydraulic resistance coefficients, pressure increase, and air temperature) were determined. Within contact cooling of air in the aerothermopressor, the values of the total pressure increase in the aerothermopressor were from 1.02 to 1.04 (2–4%). Thus, the aerothermopressor use to provide contact evaporative cooling of cyclic air between the compressor stages will ensure not only compensation for pressure losses but also provides an increase in total air pressure with simultaneous cooling. Injection of liquid in a larger amount than is necessary for evaporation ensures a decrease in pressure losses in the flow path of the aerothermopressor by 15–20%. When the amount of water flow is more than 10–15%, the pressure loss becomes equal to the loss for the “dry” aerothermopressor, and with a further increase in the amount of injected liquid, they are exceeded. The values of errors in the relative increase of air pressure in the aerothermopressor measurements not exceeded 4%. The results obtained can be used in the practice of designing intercooling systems for gas turbines.

Author(s):  
J. H. Horlock ◽  
W. A. Woods

Earlier analytical and graphical treatments of gas turbine performance, assuming the working fluid to be a perfect gas, are developed to allow for ‘non-perfect’ gas effects and pressure losses. The pressure ratios for maximum power and maximum thermal efficiency are determined analytically; the graphical presentations of performance based on the earlier approach are also modified. It is shown that the optimum conditions previously determined from the ‘air standard’ analyses may be changed quite substantially by the inclusion of the ‘real’ effects.


Author(s):  
M. Bagnoli ◽  
M. Bianchi ◽  
F. Melino ◽  
P. R. Spina

In this paper, a calculation code, developed in house by the authors, able to evaluate the performance of a gas turbine with all possible fogging strategies (high pressure fogging, overspray, and interstage injection) is presented and discussed. The code has a flexible structure and can be applied to evaluate the performance of every commercial gas turbine model. The aim of the calculation code is to overcome the limits of the most widespread commercial software, especially with regard to the two phase flow compression process simulation. The calculation code was validated on results available in the literature showing a good agreement with experimental and theoretical results.


Author(s):  
M. Bagnoli ◽  
M. Bianchi ◽  
F. Melino ◽  
P. R. Spina

In this paper, a calculation code developed by DIEM – University of Bologna, able to evaluate the performance of a gas turbine with all possible fogging strategies (high pressure fogging, overspray and interstage injection) is presented and discussed. The aim of the developed calculation code is to overcome the calculation limits of the most widespread commercial software, specially with regards to the two phase flow compression process simulation. The self developed calculation code was validated on results available in literature. The developed code is standard, and can be applied to evaluate the performance of any commercial gas turbine model.


Author(s):  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto ◽  
P. R. Spina ◽  
S. Ingistov

In the last years, among all different gas turbine inlet air cooling techniques, an increasing attention to fogging approach is dedicated. The various fogging strategies seem to be a good solution to improve gas turbine or combined cycle produced power with low initial investment cost and less installation downtime. In particular, overspray fogging and interstage injection involve two-phase flow consideration and water evaporation during compression process (also known as wet compression). According to the Author’s knowledge, the field of wet compression is not completely studied and understood. In the present paper, all the principal aspects of wet compression and in particular the influence of injected water droplet diameter and surface temperature, and their effect on gas turbine performance and on the behavior of the axial compressor (change in axial compressor performance map due to the water injection, redistribution of stage load, etc.) are analyzed by using a calculation code, named IN.FO.G.T.E. (INterstage FOgging Gas Turbine Evaluation), developed and validated by the Authors.


Author(s):  
Thomas Wagner ◽  
Robert J. Burke

The desire to maintain power plant profitability, combined with current market fuel gas pricing is forcing power generation companies to constantly look for ways to keep their industrial gas turbine units operating at the highest possible efficiency. Gas Turbines Operation requires the compression of very large quantities of air that is mixed with fuel, ignited and directed into a turbine to produce torque for purposes ranging from power generation to mechanical drive of pumping systems to thrust for air craft propulsion. The compression of the air for this process typically uses 60% of the required base energy. Therefore management of the compression process efficiency is very important to maintain overall cycle efficiency. Since fouling of turbine compressors is almost unavoidable, even with modern air filter treatment, and over time results in lower efficiency and output, compressor cleaning is required to maintain gas turbine efficiency.


1970 ◽  
Author(s):  
Stephen Luchter

Gas-turbine waste heat appears to be a valuable source of energy, yet the number of installations in which this energy is utilized is minimal. The reasons for this are reviewed and a typical nonafterburning cycle is examined for both steam and an “organic” working fluid. The power level range over which each is attractive is obtained, and the costs of each are compared on a relative basis.


Author(s):  
C. F. McDonald ◽  
R. G. Adams ◽  
F. R. Bell ◽  
P. Fortescue

The gas turbine high-temperature gas-cooled reactor (HTGR) power plant combines the existing design HTGR core with a closed-cycle helium gas turbine power conversion system directly in the reactor primary circuit. The high density helium working fluid results in a very compact power conversion system. While the geometries of the helium turbomachinery, heat exchangers, and internal gas flow paths differ from air breathing gas turbines because of the nature of the working fluid and the high degree of pressurization, many of the aerodynamic, heat transfer and dynamic analytical procedures used in the design are identical to conventional open-cycle industrial gas turbine practice. This paper outlines some of the preliminary design considerations for the rotating machinery, heat exchangers, and other major primary system components for an integrated type of plant embodying multiple gas turbine loops. The high potential for further improvement in plant efficiency and capacity, for both advanced dry-cooled and waste heat power cycle versions of the direct-cycle nuclear gas turbine, is also discussed.


Author(s):  
K. K. Botros ◽  
D. Sennhauser ◽  
L. Siarkowski

Concerns about the effects of greenhouse gas emissions on the Earth’s climate have lead to a considerable focus by the public and governments on the levels of emissions that are generated by industrial activities. In Canada, it has been recognized that gas transmission systems are rated second in overall CO2 production in the Natural Gas Industry (next to gas processing). Most of the gas transmission systems are powered by gas turbines at compressor stations resulting in significant CO2 emissions (at the rate of ∼ 6 kilo tonnes/ per MW-year). This can be reduced if the CO2 can be separated from the gas turbine exhaust stream and directed for reuse or sequestration. This paper presents results of techno-thermodynamic assessment of two power cycle adjustments to increase CO2 concentrations in the exhaust gas from turbines. The working fluid in the two semi-closed cycles are made rich in CO2, thus making it easy to capture the CO2 from the flue gas by means of physical absorption techniques rather than by the conventional expensive amine adsorption methods. Additionally, the CO2 rich working fluid is shown to give rise to a higher exhaust gas temperature from the gas turbine semi-closed cycles, allowing a steam bottom cycle to be effective in augmenting the power delivered by the entire system by 50%, hence contributing to reducing emission by increasing the overall thermal efficiency of the system.


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.


Author(s):  
Scott T. Cloyd ◽  
Arthur J. Harris

The gas turbine industry has adopted the practice of rating engine performance at ISO standard conditions; 15 degrees C, 1.033 ata, 100% methane fuel, and no inlet or exhaust system pressure losses with power output referenced to the generator terminals. (ISO, 1989) While these standards are useful in putting original equipment manufacturers’ (OEM’s) ratings on an equivalent basis it is not likely that an engine would be installed or tested under these types of conditions. To account for variations in engine operating conditions equipment manufacturers’ have utilized performance correction curves to show the influence of changing one operating parameter while holding all others constant. The purpose of this paper is to review the correction curves that are used for initial project application studies, and the variations to the curves that occur when a unit is put into service as a result of the methods used to control engine operation. Sample corrections curves and a brief explanation of the correction curves are presented to illustrate the variations in the curves. The paper also presents a new method for illustrating the influence of fuel heating value and composition on engine performance for natural gas and oil fuel. All data presented is for a single shaft, constant speed gas turbine. Two shaft or three shaft gas turbines will not have these correction curves.


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