Incorporating Environmental Impacts in Strategic Redesign of an Engineered System

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Steven R. Harper ◽  
Deborah L. Thurston
Keyword(s):  
Environmental Impacts ◽  
Early Retirement ◽  
Power Plants ◽  
Electrical Power ◽  
Decision Rules ◽  
Life Cycles ◽  
Life Extension ◽  
Electrical Power System ◽  
Term Operation ◽  
Operational Life

Large engineered systems do not often live out their life cycles as originally planned. Traditional design methods do not address redesign issues that arise during long term operation of these systems. The problem of how to consider the environmental impacts of stranded assets is especially problematic, particularly during system operational changes. This paper presents a method for analysis of a dynamically changing system that includes consideration of both economic and environmental impacts. A case study of an electrical power system illustrates the approach. Using a 100yr time period and using several decision rules (e.g., keep all plants operating until planned retirement age or retire all plants 10% early), the aggregated results were derived. The best sequence of decision or decision rule can now be determined by the highest multiattribute utility score. The best decision sequence is one that immediately retires and decommissions all fossil fueled electrical power plants, although early retirement without immediate decommissioning produces inferior utility values. There is little gained in utility when extending operational life of the plants, and as the 100yr period moves forward, all solutions collapse on the final system configuration. The results provide several insights that were gained through the ability to forecast the environmental impact caused by changes within the life cycle phases of a system, such as early retirement or operational life extension of facilities.

Assessment and Planning of the Electrical Systems in Mexican Refineries by 2014

2011 ◽  
Author(s):  
Luis Ivan Ruiz Flores ◽  
J. Hugo Rodri´guez Marti´nez ◽  
Guillermo D. Taboada ◽  
Javier Pano Jimenez
Keyword(s):  
Power Systems ◽  
Power Plants ◽  
Electrical Power ◽  
Refining Industry ◽  
Oil Refining ◽  
Electrical Power System ◽  
Electrical Power Systems ◽  
New Process ◽  
Process Plants ◽  
Petroleum Company

Nowadays the refining sector in Mexico needs to increase the quantity and quality of produced fuels by installing new process plants for gasoline and ultra low sulphur diesel. These plants require the provision of electricity and steam, among other services to function properly, which can be supplied by the power plants currently installed in each refinery through an expansion of their generation capacity. These power plants need to increase its production of electricity and steam at levels above their installed capacity, which involves the addition of new power generating equipment (gas or steam turbo-generators) as well as the raise of the electrical loads. Currently, the Mexican Petroleum Company (PEMEX) is planning to restructure their electrical and steam systems in order to optimally supply the required services for the production of high quality fuels. In this paper the present status of the original electrical power systems of the refineries is assessed and the electrical integration of new process plants in the typical schemes is analyzed. Also this paper shows the conceptual schemes proposed to restructure the electrical power system for two refineries and the strategic planning focused on implement the modifications required for the integration of new process plants that will demand about 20 MW for each refinery by 2014. The results of the analysis allowed to identify the current conditions of the electrical power systems in the oil refining industry or National Refining Industry (NRI), and thereby to offer technical solutions that could be useful to engineers facing similar projects.

An Intelligent Hybrid Model for Bus Load Forecasting in Electrical Short-Term Operation Tasks

2012 ◽  
pp. 540-562
Author(s):  
Ricardo Menezes Salgado ◽  
Takaaki Ohishi ◽  
Rosangela Ballini
Keyword(s):  
Power System ◽  
Hybrid Model ◽  
Electrical Power ◽  
Load Forecasting ◽  
Electrical Power System ◽  
Term Operation ◽  
Operating Load ◽  
Conventional Models ◽  
Safe Operating

The main objective of this chapter is to present a hybrid model for bus load forecasting. This approach represents an essential tool for the operation of the electrical power system and the hybrid model combines a bus clustering process and a load forecasting model. As a case study, the model was applied to the real Brazilian electrical system, and the results revealed a performance similar to that of conventional models for bus load forecasting, but about 14 times faster. The results are compatible with the safe operating load levels for the Brazilian electrical power system and have proved to be adequate for use in real operation tasks.

Electrical Power System Modeling of Atucha II Nuclear Power Plant Using etap

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Nicolás Alejandro Malinovsky
Keyword(s):  
Power System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Electrical Power ◽  
Analysis Tool ◽  
Plant Design ◽  
Electrical Power System ◽  
Power Circuit ◽  
Electrical Systems

This work shows the introduction of the Electrical Power System Analysis (etap) software as a calculation and analysis tool for power electrical systems of the nuclear power plants (NPP) under the orbit of Nucleoeléctrica Argentina S.A (NASA). Through the use of the software, the model of the electrical power system of the Atucha II NPP was developed. To test the functionality of the modeled electrical power circuit, studies of load flow and short-circuit analysis were conducted, yielding satisfactory results, which were contrasted with the plant design values. Once the model has been validated, this will be the basis for carrying out different studies in the plant through simulation. Furthermore, with the incorporation of etap as a fundamental calculation and analysis tool for power electrical systems at the company's engineering departments, it is expected to improve the safety, operation, quality, reliability, and maintenance of both the Atucha II NPP electrical power system and the other nuclear power plants operated by Nucleoeléctrica Argentina S.A.

THE LIFE ASSESSMENT OF STEAM TURBINE ROTORS FOR FOSSIL POWER PLANTS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4371-4376
Author(s):  
SUNGHO CHANG ◽  
GEEWOOK SONG ◽  
BUMSHIN KIM ◽  
JUNGSEB HYUN ◽  
JEONGSOO HA
Keyword(s):  
Power Plant ◽  
Steam Turbine ◽  
Rotational Speed ◽  
Power Plants ◽  
Thermal Power ◽  
Creep Damage ◽  
Life Assessment ◽  
Life Extension ◽  
Start Up ◽  
Operational Life

The operational mode of thermal power plants has been changed from base load to duty cycle. From the changeover, fossil power plants cannot avoid frequent thermal transient states, for example, start up and stop, which results in thermal fatigue damage at the heavy section components. The rotor is the highest capital cost component in a steam turbine and requires long outage for replacing with a new one. For an optimized power plant operational life, inspection management of the rotor is necessary. It is known in general that the start-up and shutdown operations greatly affect the steam turbine life. The start-up operational condition is especially severe because of the rapid temperature and rotational speed increase, which causes damage and reduction of life of the main components life of the steam turbine. The start-up stress of a rotor which is directly related to life is composed of thermal and rotational stresses. The thermal stress is due to the variation of steam flow temperature and rotational stress is due to the rotational speed of the turbine. In this paper, the analysis method for the start-up stress of a rotor is proposed, which considers simultaneously temperature and rotational speed transition, and includes a case study regarding a 500MW fossil power plant steam turbine rotor. Also, the method of quantitative damage estimation for fatigue-creep damage to operational conditions, is described. The method can be applied to find weak points for fatigue-creep damage. Using the method, total life consumption can be obtained, and can be also be used for determining future operational modes and life extension of old fossil power units.

Multi-Objective Economic Emission Load Dispatch Solution Using Evolutionary Algorithm with and without Considering Wind Power Penetration and Valve Point Effect

2014 ◽  
Vol 626 ◽  
pp. 177-183
Author(s):  
K. Thenmalar ◽  
S. Ramesh ◽  
K.S. Anuja
Keyword(s):  
Quadratic Programming ◽  
Power System ◽  
Wind Power ◽  
Power Plants ◽  
Electrical Power ◽  
Electrical Energy ◽  
Fuel Cost ◽  
Electrical Power System ◽  
Bacterial Foraging Optimization ◽  
Multi Objective

The electrical power system is considered as the most complex man-made systems mainly due to their wide geographical coverage. Electrical energy industries contributes environmental pollution which rise questions concern environmental protection and methods of eliminating or reducing pollution from power plants either by design or by operational strategies. Electric power plants are mainly aimed to operate al low fuel cost strategies .In this paper a Multi –Objective Economic Emission Load Dispatch problem is solved to minimize the emission of nitrogen oxides (NOx) , oxides of other fuels that release during generation of electricity and fuel cost considering both Thermal generators and Wind turbines. A large number of iterations and oscillation are those of the major concern in solving the economic load dispatch problem by using the BFO(bacterial foraging optimization) method. By applying BFO method the economic dispatch problem is optimized to minimize the total generation cost of a power system while satisfying various equality and inequality constraints. The effect of Wind power on overall emission is also investigated here using Quadratic programming by wolf’s method. This method has better convergence characteristic. Wolf’s method is an extended simplex procedure which can be applied to Quadratic programming problems in which all the problem variables are non-negative.

Recent Improvements in Toughness Prediction of Cast Duplex Stainless Steel Components

2019 ◽  
Author(s):  
Patrick Le Delliou ◽  
Sébastien Saillet
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Power Plants ◽  
Impact Test ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Thermal Ageing ◽  
Life Extension ◽  
Term Operation ◽  
Safety Margins

Abstract Thermal ageing of cast duplex stainless steel components is a concern for long-term operation of EDF nuclear power plants. The thermal ageing embrittlement results from the microstructural evolution of the ferrite phase (spinodal decomposition), and can reduce the fracture toughness properties of the steel. In addition, it is necessary to consider manufacturing quality and the possible occurrence of casting defects such as shrinkage cavities. In a context of life extension, it is important to assess the safety margins to crack initiation and crack propagation instability. One major input of the assessment methodology is the toughness value of the thermally aged component. Recent work conducted at EDF R&D to improve the accuracy and the conservativeness of the toughness prediction has led to the development of new prediction formulae. The toughness prediction relies on three steps: • estimation of the Charpy impact test values at 20 and 320°C using the chemical composition of the steel and the aging conditions (temperature and duration), • estimation of the J-R curve at 20 and 320°C - defined by a power law J = CΔan - thanks to correlations between n and C and the Charpy impact test values, • estimation of the J-R curve at any temperature between 20 and 320°C thanks to interpolation formulae. The paper presents the experimental data used to develop the formulae, the formulae themselves and some elements of validation.

Large EDF Tests on Aged Cast Duplex Stainless Steel Components: Part I — Reduced Scale Tests

2015 ◽  
Author(s):  
Patrick Le Delliou ◽  
Sébastien Saillet ◽  
Georges Bezdikian
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Structural Evolution ◽  
Thermal Ageing ◽  
Life Extension ◽  
Term Operation ◽  
Integrity Assessment ◽  
Safety Margins

Thermal ageing of cast duplex stainless steel primary loops components (elbows, pump casings and branch connections) is a concern for long-term operation of EDF nuclear power plants. The thermal ageing embrittlement results from the micro-structural evolution of the ferrite phase (spinodal decomposition), and can reduce the fracture toughness properties of the steel. In addition, it is necessary to consider manufacturing quality and the possible occurrence of casting defects such as shrinkage cavities. In a context of life extension, it is important to assess the safety margins to crack initiation and crack propagation instability. This paper presents several tests conducted by EDF on aged cast duplex stainless steel NPP components, respectively on two-third scale elbows and welded mock-ups. The main characteristics of the tests are recalled, the results are presented, and finally, the lessons drawn are summarized. These tests and their detailed analyses contribute to validate and justify the methodology used by EDF in the integrity assessment of in-service cast duplex stainless steel components.

scholarly journals Recent Life Assessment Technology for Existing Steam Turbines

2005 ◽  
Author(s):  
K. Saito ◽  
A. Sakuma ◽  
M. Fukuda
Keyword(s):  
High Temperature ◽  
Power Plants ◽  
High Reliability ◽  
Thermal Power ◽  
Life Assessment ◽  
Life Extension ◽  
Steam Turbines ◽  
Term Operation ◽  
Assessment Technology ◽  
Technical Features

A large and growing portion of electricity is produced by aging thermal power plants. Although excellent, high quality materials such as CrMoV steel and 12% Cr steel, etc. are used for the steam turbines, various forms of metallurgical degradation, due to creep and fatigue, etc. affect the parts and components during long-term operation at high temperature. Extending the life of steam turbines and ensuring high reliability requires life assessment technology, scheduled repairing, conversion, modification and upgrading of components in order to provide a stable power supply. As the high temperature parts and components of aged steam turbines are mainly metallurgically damaged by creep, fatigue and the interaction of both, life assessment combined with analytical and nondestructive methods is essential for realizing strategic plant life extension. We have developed a life assessment technology that takes material degradation into consideration, and have applied the procedure to more than 650 units and 2500 components since 1983. A rotor bore replication device was developed in 1989 for the purpose of nondestructive observation of creep voids and supporting the validity of life prediction results. This paper describes the technical features and applied experience of recent life assessment technology for existing high temperature steam turbines.

scholarly journals Performance of grid-connected solar photovoltaic power plants in the Middle East and North Africa

2019 ◽  
Vol 9 (5) ◽  
pp. 3375
Author(s):  
Jalal Assadeg ◽  
Kamaruzzaman Sopian ◽  
Ahmad Fudholi
Keyword(s):  
Middle East ◽  
North Africa ◽  
Power Plants ◽  
Design Method ◽  
Electrical Power ◽  
Climatic Conditions ◽  
Electrical Power System ◽  
Pv Array ◽  
Solar Fraction ◽  
Southern Mediterranean

A conceptual design Study of a solar electrical power system using PV array for a 5.3MW as nominal power required is presented. A Bird model has been used to estimate hourly, daily, monthly and yearly solar radiation amounts. f-f-chart is a design method was chosen to simulate the fraction of the solar energy required for the load given the PV array areas and climatic conditions. Four cities in the Middle East and North Africa representing different locations at southern Mediterranean region are selected Tripoli, Alexandria, Tunisia and Gaza city. Tripoli City has the best performance for 73% of nominal Power followed by Alexandria about 66% and then Gaza around 63%, Tunisia City has lowest solar fraction about 59% according to the Monthly and annual solar fraction Data.

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