Assessment of Gas Turbine’s Cooling Systems Integrated With Bottoming Cycle

2018 ◽  
Author(s):  
Waleed El-Damaty ◽  
Mohamed Gadalla
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Plants ◽  
Turbine Blades ◽  
Cooling Systems ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Overall Efficiency

With the everlasting increase in the population, a huge surge in the electricity consumption can be noticed. Thus, the power and electricity generating power plants need to augment their performance to cope with this uprising problem. The main goal for most gas turbine power plants is to increase their efficiency and performance which can be achieved by increasing the turbine inlet temperature (TIT). However, increasing the TIT requires cooling of the turbine blades to extend its lifetime and avoid thermal stresses and oxidation rates. Usually, there are two routes to improve the turbine blade cooling, either scientist focus on the parameters that effect the cooling process such as the film cooling effectiveness, shape of holes and angle of injection, or the problem is approached from a thermodynamic point of view. It is well known that the air used to cool the turbine blades is bled from the compressor which causes a severe penalty on the thermodynamic efficiency and power output of the gas turbine. This paper main objective is to improve the gas turbine performance by lowering the temperature of the coolant lines bled from the compressor for turbine blade cooling resulting in a reduction in the amount of coolant mass flow rate required for turbine cooling which will reduce the penalty on the overall efficiency increasing it. For this purpose, three different configurations of Maisotsenko desiccant cooling systems were proposed to cool down coolant lines as well as the inlet air temperature. Optimization analysis was performed to determine the best operating parameters of the gas turbine as well as the cooling systems. Sensitivity analysis was conducted as well to investigate the effect of various variables on the gas turbine overall efficiency and the coolant mass flow rate. The results showed an increase in the overall efficiency from 42.57% to 43.83%, reduction in the amount of coolant mass flow rate that is bled from the compressor from 4.584 kg/s to 3.607 kg/s and in the cooling fraction from 4.72% to 3.9%.

Dynamics Integrated Valve Analysis for Gas Turbine System

2009 ◽  
Author(s):  
Seong G. Kang ◽  
Kune Y. Suh
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Plants ◽  
Turbine Blades ◽  
Control Valve ◽  
Operating Conditions ◽  
Stop Valve ◽  
Valve Control

A methodology and theory are developed to precisely determine the gas mass flow rate for the design of a gas turbine system manufactured for the operating conditions of nuclear and fossil power plants. From the heat exchanger or boiler to the first assembly of turbine blades, the gas passes by a stop valve, control valves and first nozzle, each device of which is connected with piping. The corresponding gas flow rate can be computed when the thermal and hydraulic conditions are defined at the stop valve, control valve and pipes. Such thermophysical properties as pressure, temperature, enthalpy and velocity specified at the inlet of each device are changed at the outlet of that device due to its structural characteristics. DIVA (Dynamics Integrated Valve Analysis) is written to predict the gas mass flow rate with reference to the Widows’ Creek type control valve.

A New Concept of Impingement Cooling for Gas Turbine Hot Parts and Its Influence on Plant Performance

2003 ◽  
Author(s):  
B. Facchini ◽  
M. Surace ◽  
S. Zecchi
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Plants ◽  
Cooling System ◽  
Impinging Jets ◽  
Plant Performance ◽  
Transfer Coefficients ◽  
Impingement Cooling

Significant improvements in gas turbine cooling technology are becoming harder as progress goes over and over. Several impingement cooling solutions have been extensively studied in past literature. An accurate and extensive numerical 1D simulation on a new concept of sequential impingement was performed, showing good results. Instead of having a single impingement plate, we used several perforated plates, connecting the inlet of each one with the outlet of the previous one. Main advantages are: absence of the negative interaction between transverse flow and last rows impinging jets (reduced deflection); better distribution of pressure losses and heat transfer coefficients among the different plates, especially when pressure drops are significant and available coolant mass flow rate is low (lean premixed combustion chamber and LP turbine stages). Practical applications can have a positive influence on both cooled nozzles and combustion chambers, in terms of increased cooling efficiency and coolant mass flow rate reduction. Calculated effects are used to analyze main influences of such a cooling system on global performances of power plants.

scholarly journals Data-Driven Air-Cooled Condenser Performance Assessment: Model and Input Variable Selection Comparison

2020 ◽  
Vol 197 ◽  
pp. 10003
Author(s):  
Simone Ghettini ◽  
Alessandro Sorce ◽  
Roberto Sacile
Keyword(s):  
Neural Network ◽  
Linear Regression ◽  
Ambient Temperature ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Empirical Model ◽  
Power Plants ◽  
Data Driven ◽  
Semi Empirical

This paper presents a data–driven model for the estimation of the performance of an aircooled steam condenser (ACC) with the aim to develop an efficient online monitoring, summarized by the condenser pressure (or vacuum) as Key Performance Indicator. The estimation of the ACC performance model was based on different dataset from three different combined cycle power plants with a gross power of above 380 MWe each, focusing on stationary condition of the steam turbine. The datasets include both boundary (e.g. Ambient Temperature, Wind Speed) and operative parameters (e.g. steam mass flow rate, Steam turbine power, electrical load of the ACC fans) acquired from the power plants and some derived variable as the incondensable fraction, which calculation is here proposed as additional parameter. After a preliminary sensitivity analysis on data correlation, the paper focuses on the evaluation of different ACC Condenser models: Semi-Empirical model is described trough curves typically based on steam mass flow rate (or condenser load) and the ambient temperature as main parameters. Since monitoring based on ACC design curves Semi-Empirical models, provides biased poor results, with an error of about 15%, the curves parameters were estimated basing on training data set. Other two data driven models were presented, basing on a neural network modelling and multi linear regression technique and compared on the base of the reduced number of input at first and then including aldo the other process variables in the prediction of the condenser back pressure. Estimate the parameters of the Semi-Empirical model, results in a better prediction if just steam mass flow rate and ambient temperature are available, with an error of the 7%, thanks to the knowledge contained within the “curves shapes”, with respect to linear regression (8.3%) and Neural Network models (7.6%). Higher accuracy can be then obtained by considering a larger number of operative parameters and exploiting more complex data-driven model. With a higher number of features, the neural network model has proved a higher accuracy than the linear regression model. In fact, the mean percentage error of the NN model (2.6%), in all plant operating conditions, is slightly lower than the error of the linear regression model, but presents and much lower than the mean error of the Semi-Empirical model thanks to the additional data-based knowledge.

Performance Study of a 1 MW Gas Turbine Using Variable Geometry Compressor and Turbine Blade Cooling

2010 ◽  
Author(s):  
Cleverson Bringhenti ◽  
Jesuino Takachi Tomita ◽  
Joa˜o Roberto Barbosa
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Turbine Blades ◽  
Axial Flow ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Performance Study ◽  
Turbine Blade Cooling ◽  
Blade Cooling

This work presents the performance study of a 1 MW gas turbine including the effects of blade cooling and compressor variable geometry. The axial flow compressor, with Variable Inlet Guide Vane (VIGV), was designed for this application and its performance maps synthesized using own high technological contents computer programs. The performance study was performed using a specially developed computer program, which is able to numerically simulate gas turbine engines performance with high confidence, in all possible operating conditions. The effects of turbine blades cooling were calculated for different turbine inlet temperatures (TIT) and the influence of the amount of compressor-bled cooling air was studied, aiming at efficiency maximization, for a specified blade life and cooling technology. Details of compressor maps generation, cycle analysis and blade cooling are discussed.

scholarly journals Off-Design Performances of an Organic Rankine Cycle for Waste Heat Recovery from Gas Turbines

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1105 ◽  
Author(s):  
Carlo Carcasci ◽  
Lapo Cheli ◽  
Pietro Lubello ◽  
Lorenzo Winchler
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Ambient Air ◽  
Air Mass

This paper presents an off-design analysis of a gas turbine Organic Rankine Cycle (ORC) combined cycle. Combustion turbine performances are significantly affected by fluctuations in ambient conditions, leading to relevant variations in the exhaust gases’ mass flow rate and temperature. The effects of the variation of ambient air temperature have been considered in the simulation of the topper cycle and of the condenser in the bottomer one. Analyses have been performed for different working fluids (toluene, benzene and cyclopentane) and control systems have been introduced on critical parameters, such as oil temperature and air mass flow rate at the condenser fan. Results have highlighted similar power outputs for cycles based on benzene and toluene, while differences as high as 34% have been found for cyclopentane. The power output trend with ambient temperature has been found to be influenced by slope discontinuities in gas turbine exhaust mass flow rate and temperature and by the upper limit imposed on the air mass flow rate at the condenser as well, suggesting the importance of a correct sizing of the component in the design phase. Overall, benzene-based cycle power output has been found to vary between 4518 kW and 3346 kW in the ambient air temperature range considered.

Effects of Fe3O4/Water Nanofluid on the Efficiency of a Curved Pipe

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Milad Kelidari ◽  
Ali Jabari Moghadam
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Volume Concentration ◽  
Volume Fraction ◽  
Working Fluid ◽  
Radius Of Curvature ◽  
Dean Number ◽  
Curved Pipe ◽  
Overall Efficiency

Different-radius of curvature pipes are experimentally investigated using distilled water and Fe3O4–water nanofluid with two different values of the nanoparticle volume fraction as the working fluids. The mass flow rate is approximately varied from 0.2 to 0.7 kg/min (in the range of laminar flow); the wall heat flux is nearly kept constant. The experimental results reveal that utilizing the nanofluid increases the convection heat transfer coefficient and Nusselt number in comparison to water; these outcomes are also observed when the radius of curvature is decreased and/or the mass flow rate is increased (equivalently, a rise in Dean number). The resultant pressure gradient is, however, intensified by an increase in the volume concentration of nanoparticles and/or by a rise in Dean number. For any particular working fluid, there is an optimum mass flow rate, which maximizes the system efficiency. The overall efficiency can be introduced to include hydrodynamic as well as thermal characteristics of nanofluids in various geometrical conditions. For each radius of curvature, the same overall efficiency may be achieved for two magnitudes of nanofluid volume concentration.

Flow Field in the Tip Gap of a Planar Cascade of Turbine Blades

1989 ◽  
Vol 111 (3) ◽  
pp. 276-283 ◽  
Author(s):  
M. Yaras ◽  
Yingkang Zhu ◽  
S. A. Sjolander
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Difference ◽  
Good Accuracy ◽  
Flow Direction ◽  
Turbine Blades ◽  
Rate Distribution ◽  
Velocity Magnitude ◽  
The Relationship

Measurements are presented for the flow in the tip gap of a planar cascade of turbine blades. Three clearances of from 2.0 to 3.2 percent of the blade chord were considered. Detailed surveys of the velocity magnitude, flow direction, and total pressure within the gap were supplemented by blade surface and endwall static pressure measurements. The results help to clarify the relationship between the leakage mass flow rate distribution and the driving pressure differences. It was found that even for the present relatively large clearances, fluid near the endwall experiences a pressure difference that is comparable with the blade pressure difference. It is also shown that a simple model can predict with good accuracy the mass flow rate distribution and the magnitude and direction of the velocity vectors within the gap.

Exergoeconomic Analysis of Intercooled, Reheated and Recuperated Gas Turbine Cycles With Air Film Blade Cooling

2018 ◽  
Author(s):  
Waleed El-Damaty ◽  
Mohamed Gadalla
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Turbine Blades ◽  
Cost Calculation ◽  
Theory Approach ◽  
Cooling Systems ◽  
Thermodynamic Performance ◽  
Exergoeconomic Analysis ◽  
The Cost

For many years, thermodynamic analysis was considered to be the principal tool that is used to predict the performance of a power plant. Recently, the environmental effect and the cost of power plants have been considered as important as the thermodynamic performance in design of power plants. Thus, researchers started to adopt a relevantly new approach called the exergoeconomic analysis which combines the thermodynamic technicalities as well as the economic analysis to design power plants. The exergoeconomic analysis provides crucial information that helps in foreseeing not only the thermodynamic performance but also all economic variables related to power plants. Increasing the efficiency of the power plant has been the major concern in power plants. Thus, the global approach of reaching high turbine inlet temperatures to improve the efficiency of power plants, has exposed the turbine blades to some serious problems. Thereby, cooling the turbine blades has become an important aspect that needs to be taken care of during the power plant operation. In this paper, a cooled gas turbine with intercooler, recuperator and reheater is adopted where it is incorporated with a cooling system. An exergoeconomic analysis accompanied by a sensitivity analysis was performed on the gas turbine cycle to determine the exergo-economic factor and the relative cost difference in addition to study the effect of different variables on the gas turbine thermal and exergetic efficiency, net specific work and the total cost rate. Average cost theory approach was adopted from various thermo-economic methodologies to determine the cost calculation during this investigation. The results showed a reduction in the total coolant mass flow rate in the base case where no cooling systems are integrated from 3.349 kg/s to 3.01 kg/s, 2.995 kg/s and 2.977 kg/s in the case of integrating the cooling systems triple stage Maisotsenko desiccant, triple stage precooling Maisotsenko desiccant and triple stage extra cooling Maisotsenko desiccant, respectively. Accordingly, the thermal efficiency has increased to reach 52.69%, 52.89% and 53.12% by the integration of TS-MD, TS-PMD and TS-EMD cooling systems, respectively.

Thermodynamic Analysis of an Integrated Solar-Based Multi-Stage Flash Desalination System

2012 ◽  
Author(s):  
Diab W. Abueidda ◽  
Mohamed Gadalla
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Plants ◽  
Rankine Cycle ◽  
Distillation Unit ◽  
Second Law ◽  
Exergy Destruction ◽  
Steam Generation ◽  
Multi Stage

Worldwide concern about the scarcity of global water resources is increasing day by day. In Gulf countries, most power plants are co-generation power desalting plants (CPDP) that generate electric energy and also produce fresh water through the desalination of seawater. Nowadays, renewable energy provides a viable solution to the scarcity of energy resources and an environmental friendly option of global economy. In this paper, thermodynamic analyses have been performed on an integrated solar-based multi-stage flash desalination/Rankine cycle system. The respective losses as well as the first-law and second-law efficiencies for the system have been evaluated. The first-law and second-law efficiencies of the solar field were found to be 61.70% and 31.74%, respectively. The solar thermal field is based on direct steam generation method. Moreover, the mass flow rate through the Rankine cycle has been optimized to produce the maximum power. The optimal mass flow rate through the Rankine cycle found to be 51 kg/s. Furthermore, this paper presents and investigates a model of distillation plant that can use the heat rejected from the condenser of the Rankine cycle. The model is analyzed and validated with other results gained from literature. It found that the highest exergy destruction through the distillation unit occurs within the stages of the MSF unit. The percentage of exergy destruction in the MSF stages was found to be 75.41% of the total exergy destruction in the distillation unit. Additionally, this study verifies that increasing number of MSF stages decreases the percentage of exergy destruction.

Evaluation of Axial Compressor Characteristics Under Overspray Condition

2013 ◽  
Author(s):  
Chihiro Myoren ◽  
Yasuo Takahashi ◽  
Manabu Yagi ◽  
Takanori Shibata ◽  
Tadaharu Kishibe
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Water Mass ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Test Facility ◽  
Compressor Performance ◽  
Water Mass Flow Rate

An axial compressor was developed for an industrial gas turbine equipped with a water atomization cooling (WAC) system, which is a kind of inlet fogging technique with overspray. The compressor performance was evaluated using a 40MW-class test facility for the advanced humid air turbine system. A prediction method to estimate the effect of WAC was developed for the design of the compressor. The method was based on a streamline curvature (SLC) method implementing a droplet evaporation model. Four test runs with WAC have been conducted since February 2012. The maximum water mass flow rate was 1.2% of the inlet mass flow rate at the 4th test run, while the design value was 2.0%. The results showed that the WAC decreased the inlet and outlet temperatures compared with the DRY (no fogging) case. These decreases changed the matching point of the gas turbine, and increased the mass flow rate and the pressure ratio by 1.8% and 1.1%, respectively. Since prediction results agreed with the results of the test run qualitatively, the compressor performance improvement by WAC was confirmed both experimentally and analytically. The test run with the design water mass flow rate is going to be conducted in the near future.

Sign in / Sign up

Export Citation Format

Share Document