Techno-Economic Evaluation of Commercially Available High Fogging Systems

2005 ◽  
Author(s):  
Sasha M. Savic ◽  
Katharina E. Rostek ◽  
Daniel K. Klaesson
Keyword(s):  
Gas Turbine ◽  
System Integration ◽  
Negative Impact ◽  
Water Injection ◽  
Hot Water ◽  
Safe Operation ◽  
Compressor Blades ◽  
Surge Margin ◽  
Compressor Surge ◽  
Pressure Swirl

High fogging (wet compression, spray inter-cooling) is a technology used for gas turbine (GT) power augmentation. By evaporative spray inter-cooling of the air during compression, which is the main physical effect associated with the HF, a 5–7% power boost of the GT (for each percent of injected water per mass of air) is achieved. HF of a gas turbine can be accomplished using different spray technologies. In this study three different, commercially available spray technologies — pressure-swirl, hot water injection and air-assisted atomization — are compared regarding both technical and economical benefits and risks. The comparison is based on droplet sizing results, system complexity, the feasibility of system integration into the GT’s control and plant operation concept, GT performance and operational and additional O&M costs. It is also known that high fogging carries certain risks to the safe operation of a GT, such as compressor blades erosion, reduction in compressor surge margin and cooling airflows. To minimize the negative impact of high fogging, it is therefore important to select the most appropriate high fogging system as well as to provide for its full engine integration.

Performance Prediction of Gas Turbine Under Different Strategies Using Low Heating Value Fuel

2013 ◽  
Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Equivalence Ratio ◽  
Safe Operation ◽  
Engine Operation ◽  
Heating Value ◽  
Gasification Process ◽  
Surge Margin ◽  
And Performance ◽  
Industrial Gas Turbine

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.

scholarly journals Surge and Stall Detection Using Acoustic Analysis for Gas Turbine Hybrid Cycles

2019 ◽  
Author(s):  
Keishaly Cabrera Cruz ◽  
Paolo Pezzini ◽  
Lawrence Shadle ◽  
Kenneth M. Bryden
Keyword(s):  
Gas Turbine ◽  
Natural Frequencies ◽  
Acoustic Analysis ◽  
General Nature ◽  
Acoustic Sensors ◽  
Frequency Range ◽  
Surge Margin ◽  
Compressor Surge ◽  
Surge Line ◽  
Transient Operations

Abstract Compressor dynamics were studied in a gas turbine – fuel cell hybrid power system having a larger compressor volume than traditionally found in gas turbine systems. This larger compressor volume adversely affects the surge margin of the gas turbine. Industrial acoustic sensors were placed near the compressor to identify when the equipment was getting close to the surge line. Fast Fourier transform (FFT) mathematical analysis was used to obtain spectra representing the probability density across the frequency range (0–5000 Hz). Comparison between FFT spectra for nominal and transient operations revealed that higher amplitude spikes were observed during incipient stall at three different frequencies, 900, 1020, and 1800 Hz. These frequencies were compared to the natural frequencies of the equipment and the frequency for the rotating turbomachinery to identify more general nature of the acoustic signal typical of the onset of compressor surge. The primary goal of this acoustic analysis was to establish an online methodology to monitor compressor stability that can be anticipated and avoided.

Aerodynamic Instability and Life Limiting Effects of Inlet and Interstage Water Injection Into Gas Turbines

2005 ◽  
Author(s):  
Klaus Brun ◽  
Rainer Kurz ◽  
Harold R. Simmons
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Water Injection ◽  
Axial Compressor ◽  
Careful Analysis ◽  
Operating Conditions ◽  
Aerodynamic Stability ◽  
Surge Margin ◽  
Power Enhancement ◽  
Aerodynamic Instability

Gas turbine power enhancement technologies such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection are being employed by end-users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Particularly, the effect of these add-on devices, off-design operating conditions, non-standard fuels, and compressor degradation/fouling on the gas turbine’s axial compressor surge margin and aerodynamic stability is often overlooked. Nonetheless, compressor aerodynamic instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure; i.e., a careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses non-standard fuels. This paper discusses a simplified method to evaluate the principal factors that affect the aerodynamic stability of a single shaft gas turbine’s axial compressor. As an example, the method is applied to a frame type gas turbine and results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities but that it can be a contributing factor if for other reasons the machine’s surge margin is already slim. The approach described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure.

Compressor Instability Analysis Within a Hybrid System Subject to Cycle Uncertainties

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Alessandra Cuneo ◽  
Alberto Traverso ◽  
Aristide F. Massardo
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Stochastic Analysis ◽  
High Speed ◽  
Operating Conditions ◽  
Operational Parameters ◽  
Surge Margin ◽  
Speed Range ◽  
Compressor Surge

The dynamic modeling of energy systems can be used for different purposes, obtaining important information both for the design phase and control system strategies, increasing the confidence during experimental phase. Such analysis in dynamic conditions is generally performed considering fixed values for both geometrical and operational parameters such as volumes, orifices, but also initial temperatures, pressure. However, such characteristics are often subject to uncertainty, either because they are not known accurately or because they may depend on the operating conditions at the beginning of the relevant transient. With focus on a gas turbine fuel cell hybrid system (HS), compressor surge may or may not occur during transients, depending on the aforementioned cycle characteristics; hence, compressor surge events are affected by uncertainty. In this paper, a stochastic analysis was performed taking into account an emergency shut-down (ESD) in a fuel cell gas turbine HS, modeled with TRANSEO, a deterministic tool for the dynamic simulations. The aim of the paper is to identify the main parameters that impact on compressor surge margin. The stochastic analysis was performed through the response sensitivity analysis (RSA) method, a sensitivity-based approximation approach that overcomes the computational burden of sampling methods. The results show that the minimum surge margin occurs in two different ranges of rotational speed: a high-speed range and a low-speed range. The temperature and geometrical characteristics of the pressure vessel, where the fuel cell is installed, are the two main parameters that affect the surge margin during an emergency shut down.

T100 Micro Gas Turbine Converted to Full Humid Air Operation: Test Rig Evaluation

2014 ◽  
Author(s):  
Ward De Paepe ◽  
Marina Montero Carrero ◽  
Svend Bram ◽  
Francesco Contino
Keyword(s):  
Energy Transfer ◽  
Gas Turbines ◽  
Water Injection ◽  
Test Rig ◽  
Humid Air ◽  
Limited Energy ◽  
Surge Margin ◽  
Heat Demand ◽  
Compressor Surge ◽  
Efficiency Increase

Micro Gas Turbines (mGTs) are very cost effective in small-scale Combined Heat and Power (CHP) applications. By simultaneously producing electric and thermal power, a global CHP efficiency of 80 % can be reached. However the low electric efficiency of 30 % makes the mGT profitability strongly dependent on the heat demand. This makes the mGT less attractive for applications with a non-continuous heat demand like domestic applications. Turning the mGT into a micro Humid Air Turbine (mHAT) is a way to decouple the power production from the heat demand. This new approach allows the mGT to keep running with water injection and thus higher electric efficiency during periods with no or lower heat demand. Simulations of the mHAT predicted a substantial electric efficiency increase due to the introduction of water in the cycle. The mHAT concept with saturation tower was however never tested experimentally. In this paper, we present the results of our first experiments on a modified Turbec T100 mGT. As a proof of concept, the mGT has been equipped with a spray saturation tower to humidify the compressed air. The primary goal of this preliminary experiments was to evaluate the new test rig and identify its shortcomings. The secondary goal was to gain insight in the mHAT control, more precisely the start-up strategy. Two successful test runs of more than 1 hour with water injection at 60 kWe were performed, resulting in stable mGT operation at constant rotation speed and pressure ratio. Electric efficiency was only slightly increased from 24.3 % to 24.6 % and 24.9 % due to the limited amount of injected water. These changes are however in the range of the accuracy on the measurements. The major shortcomings of the test rig were compressor surge margin reduction and the limited energy transfer in the saturation tower. Surge margin was reduced due to a pressure loss over the humidification unit and piping network, resulting in possible compressor surge. Bleeding air to increase surge margin was the solution to prevent compressor surge, but it lowers the electric efficiency by approximately 4 % absolute. The limited energy transfer was a result of a low water injection temperature and mass flow rate. The low energy transfer causes the limited efficiency increase. The first experiments on the mHAT test rig indicated its shortcomings but also its potential. Stable mGT operation was obtained and electric efficiency remained stable. By increasing the amount of injected water, the electric efficiency can be increased.

Analysis of Gas Turbine Performance in IGCC Plants Considering Compressor Operating Condition and Turbine Metal Temperature

2009 ◽  
Author(s):  
Y. S. Kim ◽  
J. J. Lee ◽  
K. S. Cha ◽  
T. S. Kim ◽  
J. L. Sohn ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Combined Cycle ◽  
Air Separation ◽  
Metal Temperature ◽  
Integrated Gasification Combined Cycle ◽  
Separation Unit ◽  
Gasification Process ◽  
Surge Margin ◽  
Compressor Surge ◽  
Integration Degree

An IGCC (integrated gasification combined cycle) plant couples a power block to a gasification block. The method of integrating a gas turbine with a gasification process is the major design option. Matching between the gas turbine and the air separation unit is especially important. This study analyzes the influences of IGCC design options on the operability and performance of the gas turbine. Another research focus is given to the estimation of the change of turbine metal temperature in the IGCC operating environment. For this purpose, a full off-design analysis of the gas turbine is used with the turbine blade cooling model. Four different syngas fuels are considered. As the integration degree becomes lower, the gas turbine power and efficiency increase. However, a lower integration degree causes a reduction of the compressor surge margin and overheating of the turbine metal. Only near 100% integration degree designs are almost free of those two problems. The syngas property also affects the gas turbine operation. As the heating value gets lower, the problems of surge margin reduction and metal overheating become more severe. Modifications of the compressor (adding a couple of stages) and the turbine (increasing gas path area) could solve the compressor surge problem. However, the turbine overheating problem still exists. In particular, the turbine modification is predicted to overheat turbine metal considerably.

Component Tests With a Model V84.3A Gas Turbine in the Siemens Test Facility in Berlin

2002 ◽  
Author(s):  
Christof Lechner ◽  
Bernward Mertens ◽  
Dieter Warnack ◽  
Dirk Weltersbach ◽  
Herwart Ho¨nen
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Field Measurements ◽  
Test Facility ◽  
Prediction System ◽  
Test Bed ◽  
Surge Margin ◽  
Compressor Surge ◽  
On Line ◽  
Flow Duct

In its Gas Turbine Development and Manufacturing Center in Berlin Siemens runs a test bed for gas turbine prototypes. Since the end of 1998, the new model V84.3A gas turbine has been undergoing tests at this facility. One focus of last year’s tests was on flow field measurements with pneumatic probes in the exit flow duct of the turbine at various load levels to characterize the flow in the diffuser and provide a data base. Another item was the further investigation of the compressor surge margin and the validation of a newly-developed on-line surge prediction system.

Experimental Investigations of Pressure Losses on the Performance of a Micro Gas Turbine System

2010 ◽  
Author(s):  
Jan Zanger ◽  
Axel Widenhorn ◽  
Manfred Aigner
Keyword(s):  
Steady State ◽  
Electric Power ◽  
Gas Turbine ◽  
Pressure Loss ◽  
System Stability ◽  
Pressure Losses ◽  
Micro Gas Turbine ◽  
Additional Pressure ◽  
Surge Margin ◽  
Compressor Surge

Pressure losses between compressor outlet and turbine inlet are a major issue of overall efficiency and system stability for a SOFC/MGT hybrid power plant system. The goal of this work is the detailed analysis of the effects of additional pressure losses on MGT performance in terms of steady-state and transient conditions. The experiments were performed at the micro gas turbine test rig at the German Aerospace Centre in Stuttgart using a butterfly control valve to apply additional pressure loss. The paper reports electric power and pressure characteristics at steady-state conditions, as well as, a new surge limit, which was found for the Turbec T100 micro gas turbine. Furthermore, the effects of additional pressure loss on compressor surge margin are quantified and a linear relation between relative surge margin and additional pressure loss is shown. For transient variation of pressure loss at constant turbine speed time delays are presented and a compensation issue of the commercial gas turbine controller is discussed. Finally, bleed-air blow-off and reduction of turbine outlet temperature are introduced as methods of increasing surge margin. It is quantified that both methods have a substantial effect on compressor surge margin. Furthermore, a comparison between both methods is given in terms of electric power output.

scholarly journals Evaluation of Shale Oil as a Utility Gas Turbine Fuel

1982 ◽  
Author(s):  
R. A. Sederquist ◽  
J. Frese ◽  
J. McVey ◽  
C. L. Knauf ◽  
H. Schreiber
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Electric Power Research Institute ◽  
Hot Water ◽  
Petroleum Distillate ◽  
Shale Oil ◽  
Mass Ratio ◽  
Percent Nitrogen ◽  
Distillate Fuel ◽  
Engine Power

The work described in this paper was conducted under an Electric Power Research Institute (EPRI) Contract RP1691-2, “Evaluation of Shale Oil Residual as a Utility Gas Turbine Fuel.” An FT4A-9 engine was run at Long Island Lighting Company (LILCO), and a selected single-can combustor from the LILCO engine was run at United Technologies on No. 2 petroleum distillate fuel and hydrotreated Paraho shale oil residual, with and without water injection. The use of hot water injection was successfully demonstrated, with reduced NOx emissions and low smoke on both fuels. The EPA NOx limit of 125 ppm for fuels containing 0.25 percent nitrogen or greater was close to being met at 18.5-MW engine power with shale oil residual at a water-to-fuel mass ratio of 0.79.

A Study of the Effect of Deterioration on Compressor Surge Margin in Constant-Speed, Single-Shaft Gas Turbine Engines

1986 ◽  
Author(s):  
Robert E. Dundas
Keyword(s):  
Gas Turbine ◽  
Constant Speed ◽  
Temperature Control System ◽  
Operating Line ◽  
Ambient Temperatures ◽  
Flow Capacity ◽  
Surge Margin ◽  
Compressor Surge ◽  
Compressor Map ◽  
Filter Clogging

A mathematical model of a constant-speed single-shaft gas turbine was devised using a typical compressor map. Performance calculations were performed at various ambient temperatures based on a standard temperature control system for a number of possible component deterioration modes. The effects on compressor operating line were determined. It was found that only two modes of deterioration; reduction of compressor flow capacity either through fouling or through erosion and closing of turbine nozzle diaphragms, moved the operating line toward surge. Inlet filter clogging must also be minimized in order to avoid surge because resulting distortion can induce stall and surge.

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