scholarly journals Benchmarking Engineering, Procurement and Construction (EPC) Power Plant Projects by Means of Series Two-Stage DEA

Electricity ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Ioannis E. Tsolas
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Combined Cycle ◽  
Operating Efficiency ◽  
Data Envelopment ◽  
Power Sector ◽  
Two Stage ◽  
Second Stage ◽  
Ex Ante ◽  
Open Cycle

A lot of companies in the power sector use Engineering, Procurement, and Construction (EPC) contracts for complex infrastructure projects such as power plants. This paper presents a series two-stage data envelopment analysis (DEA) approach for the ex ante benchmarking of EPC power plant projects. The current study aims to improve over single-stage DEA and evaluate the efficiency of a group of twelve domestic (located in Greece) and international natural gas-fired power plant projects of different technologies (combined cycle power plant (CCPP) projects with single and multi-shaft configuration, and open cycle power plant (OCPP) projects) by employing a series two-stage DEA model. In the first stage, performance of the EPC mode is evaluated, whereas in the second stage the plant annual operational efficiency is assessed. In the light of the results, there is a lower level of performance in the EPC mode than in operating efficiency. The OCPP projects have the best operating efficiency, whereas they are ranked in-between the CCPP projects with single and multi-shaft configuration in EPC mode performance.

scholarly journals Numerical Study of the Axial Gap and Hot Streak Effects on Thermal and Flow Characteristics in Two-Stage High Pressure Gas Turbine

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2654 ◽  
Author(s):  
Myung Gon Choi ◽  
Jaiyoung Ryu
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Suction Side ◽  
Combined Cycle ◽  
Maximum Temperature ◽  
Two Stage ◽  
Second Stage

Combined cycle power plants (CCPPs) are becoming more important as the global demand for electrical power increases. The power and efficiency of CCPPs are directly affected by the performance and thermal efficiency of the gas turbines. This study is the first unsteady numerical study that comprehensively considers axial gap (AG) in the first-stage stator and first-stage rotor (R1) and hot streaks in the combustor outlet throughout an entire two-stage turbine, as these factors affect the aerodynamic performance of the turbine. To resolve the three-dimensional unsteady-state compressible flow, an unsteady Reynolds-averaged Navier–Stokes (RANS) equation was used to calculate a k-ω SST γ turbulence model. The AG distance d was set as 80% (case 1) and 120% (case 3) for the design value case 2 (13 mm or d/Cs1 = 0.307) in a GE-E3 gas turbine model. Changes in the AG affect the overall flow field characteristics and efficiency. If AG decreases, the time-averaged maximum temperature and pressure of R1 exhibit differences of approximately 3 K and 400 Pa, respectively. In addition, the low-temperature zone around the hub and tip regions of R1 and second-stage rotor (R2) on the suction side becomes smaller owing to a secondary flow and the area-averaged surface temperature increases. The area-averaged heat flux of the blade surface increases by a maximum of 10.6% at the second-stage stator and 2.8% at R2 as the AG decreases. The total-to-total efficiencies of the overall turbine increase by 0.306% and 0.295% when the AG decreases.

Energy Analysis of a Lignite-Fueled Power Plant With a Two-Stage Predrying System

2017 ◽  
Author(s):  
Xin Zhu ◽  
Chang’an Wang ◽  
Chunli Tang ◽  
Defu Che
Keyword(s):  
Power Plant ◽  
Heat Source ◽  
Flue Gas ◽  
Power Plants ◽  
Energy Analysis ◽  
Exhaust Gas ◽  
Two Stage ◽  
Second Stage ◽  
Drying System ◽  
Steam Drying

Performance of lignite-fueled power plants can be improved by predrying the lignite and it is influenced by the characteristics of drying heat source. Heat source for lignite predrying in power plants can be high-temperature flue gas, boiler exhaust gas and extraction steam. Nevertheless, balance point among drying safety, lignite drying degree and drying thermal economy cannot be located using single drying heat source. In this study, a lignite-fueled power plant with a two-stage drying system was proposed. The drying system mainly contains two fluidized bed dryers — the first stage dryer and the second stage dryer. Boiler exhaust gas and extraction steam supply the heat, respectively. The proposed power plant can attain higher lignite drying degree than the power plant in which only boiler exhaust was employed. The new power plant also features higher overall efficiency for the same lignite drying degree compared with extraction steam drying power plant..

scholarly journals Benchmarking Wind Farm Projects by Means of Series Two-Stage DEA

2020 ◽  
Vol 2 (3) ◽  
pp. 365-376
Author(s):  
Ioannis E. Tsolas
Keyword(s):  
Wind Farm ◽  
Stage Structure ◽  
Operational Efficiency ◽  
Operating Efficiency ◽  
Data Envelopment ◽  
Construction Process ◽  
Two Stage ◽  
Investment Performance ◽  
Second Stage ◽  
Using Data

This paper presents a data envelopment analysis (DEA) approach to benchmark a group of wind farm (WF) projects in Greece by employing a series two-stage structure. In the first stage, the investment performance of projects is evaluated using contract data and site wind conditions, though in the second stage the WF operational efficiency is evaluated using data on production inputs and output. Inefficiency occurs in both the construction and operating stages, but the construction process appears to be more inefficient relative to the operating phase. Moreover, WF size is related to operating efficiency and sensitivity analysis results identify wind speed and WF installation capacity as the factors that affect the investment performance and operational efficiency, respectively. The proposed approach is an addition to the existing literature and it can be used by managers and facility operators.

Benchmarking the efficiencies of Indonesia’s municipal water utilities using Stackelberg data envelopment analysis

2015 ◽  
Vol 22 (4) ◽  
pp. 588-609 ◽  
Author(s):  
Andreas Wibowo ◽  
Hans Wilhelm Alfen
Keyword(s):  
Data Envelopment Analysis ◽  
The Body ◽  
Water Utilities ◽  
Data Envelopment ◽  
Two Stage ◽  
Restrictive Assumption ◽  
Content Type ◽  
Second Stage ◽  
Municipal Water ◽  
The Impact

Purpose – The purpose of this paper is to present a yardstick efficiency comparison of 269 Indonesian municipal water utilities (MWUs) and measures the impact of exogenous environmental variables on efficiency scores. Design/methodology/approach – Two-stage Stackelberg leader-follower data envelopment analysis (DEA) and artificial neural networks (ANN) were employed. Findings – Given that serviceability was treated as the leader and profitability as the follower, the first and second stage DEA scores were 55 and 32 percent (0 percent = totally inefficient, 100 percent = perfectly efficient), respectively. This indicates sizeable opportunities for improvement, with 39 percent of the total sample facing serious problems in both first- and second-stage efficiencies. When profitability instead leads serviceability, this results in more decreased efficiency. The size of the population served was the most important exogenous environmental variable affecting DEA efficiency scores in both the first and second stages. Research limitations/implications – The present study was limited by the overly restrictive assumption that all MWUs operate at a constant-return-to-scale. Practical implications – These research findings will enable better management of the MWUs in question, allowing their current level of performance to be objectively compared with that of their peers, both in terms of scale and area of operation. These findings will also help the government prioritize assistance measures for MWUs that are suffering from acute performance gaps, and to devise a strategic national plan to revitalize Indonesia’s water sector. Originality/value – This paper enriches the body of knowledge by filling in knowledge gaps relating to benchmarking in Indonesia’s water industry, as well as in the application of ensemble two-stage DEA and ANN, which are still rare in the literature.

Thermo-Economic Assessment Under Electrical Market Uncertainties of a Combined Cycle Gas Turbine Integrated With a Flue Gas-Condensing Heat Pump

2020 ◽  
Author(s):  
Alberto Vannoni ◽  
Andrea Giugno ◽  
Alessandro Sorce
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Gas Turbine ◽  
Heat Pump ◽  
Flue Gas ◽  
Power Plants ◽  
Greenhouse Gas Emission ◽  
Capital Expenditure ◽  
Combined Cycle ◽  
Gas Turbine Power Plant

Abstract Renewable energy penetration is growing, due to the target of greenhouse-gas-emission reduction, even though fossil fuel-based technologies are still necessary in the current energy market scenario to provide reliable back-up power to stabilize the grid. Nevertheless, currently, an investment in such a kind of power plant might not be profitable enough, since some energy policies have led to a general decrease of both the average price of electricity and its variability; moreover, in several countries negative prices are reached on some sunny or windy days. Within this context, Combined Heat and Power systems appear not just as a fuel-efficient way to fulfill local thermal demand, but also as a sustainable way to maintain installed capacity able to support electricity grid reliability. Innovative solutions to increase both the efficiency and flexibility of those power plants, as well as careful evaluations of the economic context, are essential to ensure the sustainability of the economic investment in a fast-paced changing energy field. This study aims to evaluate the economic viability and environmental impact of an integrated solution of a cogenerative combined cycle gas turbine power plant with a flue gas condensing heat pump. Considering capital expenditure, heat demand, electricity price and its fluctuations during the whole system life, the sustainability of the investment is evaluated taking into account the uncertainties of economic scenarios and benchmarked against the integration of a cogenerative combined cycle gas turbine power plant with a Heat-Only Boiler.

The Elephant in the Room–Gas Turbine Power

2010 ◽  
Vol 132 (12) ◽  
pp. 57-57
Author(s):  
Lee S. Langston
Keyword(s):  
Power Plant ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Electrical Power ◽  
Electric Power Industry ◽  
Hydrocarbon Fuel ◽  
Combined Cycle ◽  
Electrical Generator ◽  
Gas Turbine Exhaust

This article presents an overview of gas turbine combined cycle (CCGT) power plants. Modern CCGT power plants are producing electric power as high as half a gigawatt with thermal efficiencies approaching the 60% mark. In a CCGT power plant, the gas turbine is the key player, driving an electrical generator. Heat from the hot gas turbine exhaust is recovered in a heat recovery steam generator, to generate steam, which drives a steam turbine to generate more electrical power. Thus, it is a combined power plant burning one unit of fuel to supply two sources of electrical power. Most of these CCGT plants burn natural gas, which has the lowest carbon content of any other hydrocarbon fuel. Their near 60% thermal efficiencies lower fuel costs by almost half compared to other gas-fired power plants. Their installed capital cost is the lowest in the electric power industry. Moreover, environmental permits, necessary for new plant construction, are much easier to obtain for CCGT power plants.

Thermoeconomic Study of a Small Parabolic Trough Solar Plant

2010 ◽  
Author(s):  
M. D. Duran ◽  
E. A. Rinco´n ◽  
M. Sa´nchez
Keyword(s):  
Power Plant ◽  
Optimization Model ◽  
Power Plants ◽  
Optimization Problem ◽  
Pressure Level ◽  
Combined Cycle ◽  
Design Parameters ◽  
Parabolic Trough ◽  
Solar Plant ◽  
Solar Power Plants

This work describes the thermoeconomic study of an integrated combined cycle parabolic trough power plant. The parabolic trough plant will economize boiler activity, and thus the thermoeconomic optimization of the configuration of the boiler, including the parabolic trough plant, will be achieved. The objective is to obtain the optimum design parameters for the boiler and the size of the parabolic field. The proposal is to apply the methodology employed by Duran [1] and Valde´s et. al. [2], but with the inclusion of the parabolic trough plant into the optimization problem. It is important to point out that the optimization model be applied to a single pressure level configuration. For future works, it is proposed that the same model be applied to different configurations of integrated combined cycle solar power plants. As a result the optimum thermoeconomic design will be obtained for a parabolic trough plant used to economize the HRSG.

300 MW Combined-Cycle Plant With Integrated Coal Gasification

1984 ◽  
Author(s):  
Rolf H. Kehlhofer
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbines ◽  
Power Plants ◽  
Coal Gasification ◽  
District Heating ◽  
Combined Cycle ◽  
Liquid Fuels ◽  
Combined Cycle Plant ◽  
The Individual

In the past 15 years the combined-cycle (gas/steam turbine) power plant has come into its own in the power generation market. Today, approximately 30 000 MW of power are already installed or being built as combined-cycle units. Combined-cycle plants are therefore a proven technology, showing not only impressive thermal efficiency ratings of up to 50 percent in theory, but also proving them in practice and everyday operation (1) (2). Combined-cycle installations can be used for many purposes. They range from power plants for power generation only, to cogeneration plants for district heating or combined cycles with maximum additional firing (3). The main obstacle to further expansion of the combined cycle principle is its lack of fuel flexibility. To this day, gas turbines are still limited to gaseous or liquid fuels. This paper shows a viable way to add a cheap solid fuel, coal, to the list. The plant system in question is a 2 × 150 MW combined-cycle plant of BBC Brown Boveri with integrated coal gasification plant of British Gas/Lurgi. The main point of interest is that all the individual components of the power plant described in this paper have proven their worth commercially. It is therefore not a pilot plant but a viable commercial proposition.

Seven Years of Putnam Plant Operation: Part 1–2

1984 ◽  
Author(s):  
V. C. Tandon ◽  
D. A. Moss
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Heat Rate ◽  
Combined Cycle ◽  
High Availability ◽  
Fuel Utilization ◽  
Residual Oil ◽  
L System ◽  
Efficient Power ◽  
Plant Components

Florida Power and Light Company’s Putnam Station, one of the most efficient power plants in the FP&L system, is in a unique and enviable position from an operational viewpoint. Its operation, in the last seven years, has evolved through a triple phase fuel utilization from distillate to residual oil and finally to natural gas. This paper compares the availability/reliability of the Putnam combined cycle station and the starting reliability of the combustion turbines in each of the operating periods. A review of the data shows that high availability/reliability is not fuel selective when appropriate actions are developed and implemented to counteract the detractors. This paper also includes experience with heat rate and power degradation of various power plant components and programs implemented to restore performance.

Model of a Combined Cycle Steam Section for Use in an On-Line Fuzzy-Based Diagnosis System

2012 ◽  
Author(s):  
Rafael Barbosa ◽  
Sandro Ferreira ◽  
Raphael Duarte ◽  
Paula Ribeiro Pinto ◽  
Marília Paula e Silva
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Computer Models ◽  
Combined Cycle ◽  
Feed Water ◽  
Diagnosis System ◽  
Power Plant Equipment ◽  
Partial Load ◽  
On Line ◽  
Good Agreement

In recent years, combined cycle power plants showed remarkable progress in the safe operation and reliability of their equipment, mostly because of the reliable control and instrumentation systems available today. However, these systems cannot detect and evaluate inconsistencies in the behaviour of equipment due to failures and avoid trips caused by catastrophic events. Computer models developed to simulate the power plant equipment are often employed in diagnosis tools in order to provide accurate healthy parameters that are compared to the field measured parameters. In this work, the computer models built for the simulation of some of the main bottoming cycle equipment of a real power plant (steam turbine, HRSG, boiler feed water pumps and condenser) are described. These models were developed through characteristics maps and constitutive equations related to the fluid path analysis, implemented in Fortran language. The results provided by the developed models for each equipment show good agreement with operational data at base and partial load in simulations that covered a good part of the load domain. Due to the good agreement between the measured parameters values and those calculated through simulation, these models are intended to be included in an on-line fuzzy-based diagnosis system.

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