ADEX control of steam temperature in a combined cycle

2010 ◽  
Author(s):  
Antonio Nevado ◽  
Isaias Martin ◽  
Ricardo Requena
Keyword(s):  
Combined Cycle ◽  
Steam Temperature

Experimental Investigation Into Thermal Behaviour of Steam Turbine Components: Part 1—Temperature Measurements With Optical Probes

2012 ◽  
Author(s):  
W. F. Mohr ◽  
P. Ruffino
Keyword(s):  
Steam Turbine ◽  
Combined Cycle ◽  
Temperature Measurements ◽  
Steam Turbines ◽  
Steam Temperature ◽  
Standard Temperature ◽  
Pressure Steam ◽  
Rotor Surface ◽  
Base Load

The first-in-time application of intensity pyrometry to measure in-situ the hot rotor surface temperature of a standard, combined cycle, intermediate pressure steam turbine is presented. The data cover a cold-start and cooling from base load. The pyrometric temperatures are compared to standard temperature measurements on static turbine parts and an upstream steam temperature measured on a thermo well. It is reported, how the applicability of pyrometry in steam turbines was assessed. Details are given about a newly developed USC autoclave, which was used to measure steam transmittance, and about the measurement of the emissivity of the rotor metal. Further the steps taken towards a steam-pyrometer are shown; how it was developed, validated in terms of its precision and lifetime in hot steam environment, and how its integration to a standard turbine was prepared.

Electrical Power Generation: Fossil Fuels

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Fossil Fuels ◽  
Turbine Blades ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Steam Temperature

Nearly all electrical power is generated by rotating a coil in a magnetic field. In most cases, the coil is turned by a steam turbine operating according to the Rankine cycle. Water is boiled and heated to make high-pressure steam, which drives the turbine. The thermal efficiency is about 30–35%, and is limited by the highest steam temperature tolerated by the turbine blades. Alternatively, a gas turbine operating according to the Brayton cycle can be used. Much higher turbine inlet temperatures are possible, and the thermal efficiency is higher, typically 40%. Combined cycle generation, in which the hot exhaust from a gas turbine drives a Rankine cycle, can achieve thermal efficiencies of almost 60%. Substitution of coal-fired by combined cycle natural gas power plants can result in significant reductions in CO2 emissions.

Effect of Inlet Steam Temperature on the HP Section Efficiency of a Steam Turbine

2015 ◽  
Author(s):  
Yiping Fu ◽  
Thomas Winterberger
Keyword(s):  
Steam Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Control Valve ◽  
Combined Cycle ◽  
Steam Turbines ◽  
Steam Temperature ◽  
Load Range ◽  
Lp Turbine ◽  
The Relationship

Steam turbines for modern fossil and combined cycle power plants typically utilize a reheat cycle with High Pressure (HP), Intermediate Pressure (IP), and Low Pressure (LP) turbine sections. For an HP turbine section operating entirely in the superheat region, section efficiency can be calculated based on pressure and temperature measurements at the inlet and exhaust. For this case HP section efficiency is normally assumed to be a constant value over a load range if inlet control valve position and section pressure ratio remain constant. It has been observed that changes in inlet steam temperature impact HP section efficiency. K.C. Cotton stated that ‘the effect of throttle temperature on HP turbine efficiency is significant’ in his book ‘Evaluating and Improving Steam Turbine Performance’ (2nd Edition, 1998). The information and conclusions provided by K.C. Cotton are based on test results for large fossil units calculated with 1967 ASME steam tables. Since the time of Mr. Cotton’s observations, turbine configurations have evolved, more accurate 1997 ASME steam tables have been released, and our ability to quickly analyze large quantities of data has greatly increased. This paper studies the relationship between inlet steam temperature and HP section efficiency based on both 1967 and 1997 ASME steam tables and recent test data, which is analyzed computationally to reveal patterns and trends. With the efficiencies of various inlet pressure class HP section turbines being calculated with both 1967 and 1997 ASME steam tables, a comparison reveals different characteristics in the relationship between inlet steam temperature and HP section efficiency. Recommendations are made on how the results may be used to improve accuracy when testing and trending HP section performance.

Advances in Desuperheating Technology for Reliable Performance of Combined Cycle Power Plants (CCPP)

2005 ◽  
Author(s):  
Peter Borzsony ◽  
Sanjay V. Sherikar
Keyword(s):  
Power Plants ◽  
Current Approach ◽  
Combined Cycle ◽  
Performance Criteria ◽  
Steam Temperature ◽  
Power Stations ◽  
Reliable Performance ◽  
Overall Performance ◽  
Overall Reliability ◽  
Good Agreement

This paper focuses on the advances in desuperheating technology, their application in reliable control of steam temperature in power stations and their implication as far as the overall reliability of cycling units. Typical problems with attemperators/ desuperheaters and the current approach to desuperheater selection are reviewed. Fundamental principles that govern the overall performance in attemperation/ desuperheating are described in conjunction with the analysis and experimental work behind it. Quantifiable, and verifiable, performance criteria for selecting desuperheaters based on the application of these fundamentals are provided. A prediction tool, which is based on the fundamentals approach and shows good agreement with field experience, is described.

Exergoeconomic analysis of renewable multi-generation system

2020 ◽  
pp. 99-111
Author(s):  
Vontas Alfenny Nahan ◽  
Audrius Bagdanavicius ◽  
Andrew McMullan
Keyword(s):  
Capital Investment ◽  
Combined Cycle ◽  
Asian Countries ◽  
Generation System ◽  
Integrated Gasification Combined Cycle ◽  
Heating And Cooling ◽  
Integrated Gasification ◽  
Exergoeconomic Analysis ◽  
Main Components ◽  
The Cost

In this study a new multi-generation system which generates power (electricity), thermal energy (heating and cooling) and ash for agricultural needs has been developed and analysed. The system consists of a Biomass Integrated Gasification Combined Cycle (BIGCC) and an absorption chiller system. The system generates about 3.4 MW electricity, 4.9 MW of heat, 88 kW of cooling and 90 kg/h of ash. The multi-generation system has been modelled using Cycle Tempo and EES. Energy, exergy and exergoeconomic analysis of this system had been conducted and exergy costs have been calculated. The exergoeconomic study shows that gasifier, combustor, and Heat Recovery Steam Generator are the main components where the total cost rates are the highest. Exergoeconomic variables such as relative cost difference (r) and exergoeconomic factor (f) have also been calculated. Exergoeconomic factor of evaporator, combustor and condenser are 1.3%, 0.7% and 0.9%, respectively, which is considered very low, indicates that the capital cost rates are much lower than the exergy destruction cost rates. It implies that the improvement of these components could be achieved by increasing the capital investment. The exergy cost of electricity produced in the gas turbine and steam turbine is 0.1050 £/kWh and 0.1627 £/kWh, respectively. The cost of ash is 0.0031 £/kg. In some Asian countries, such as Indonesia, ash could be used as fertilizer for agriculture. Heat exergy cost is 0.0619 £/kWh for gasifier and 0.3972 £/kWh for condenser in the BIGCC system. In the AC system, the exergy cost of the heat in the condenser and absorber is about 0.2956 £/kWh and 0.5636 £/kWh, respectively. The exergy cost of cooling in the AC system is 0.4706 £/kWh. This study shows that exergoeconomic analysis is powerful tool for assessing the costs of products.

Exergy and sensibility analysis of each individual effect in a kraft multiple effect evaporator

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 607-618
Author(s):  
JÉSSICA MOREIRA ◽  
BRUNO LACERDA DE OLIVEIRA CAMPOS ◽  
ESLY FERREIRA DA COSTA JUNIOR ◽  
ANDRÉA OLIVEIRA SOUZA DA COSTA
Keyword(s):  
Optimization Problem ◽  
Real Data ◽  
Kraft Pulping ◽  
Steam Temperature ◽  
Input Flow ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Multiple Effect ◽  
Sensibility Analysis ◽  
Exergetic Analysis

The multiple effect evaporator (MEE) is an energy intensive step in the kraft pulping process. The exergetic analysis can be useful for locating irreversibilities in the process and pointing out which equipment is less efficient, and it could also be the object of optimization studies. In the present work, each evaporator of a real kraft system has been individually described using mass balance and thermodynamics principles (the first and the second laws). Real data from a kraft MEE were collected from a Brazilian plant and were used for the estimation of heat transfer coefficients in a nonlinear optimization problem, as well as for the validation of the model. An exergetic analysis was made for each effect individually, which resulted in effects 1A and 1B being the least efficient, and therefore having the greatest potential for improvement. A sensibility analysis was also performed, showing that steam temperature and liquor input flow rate are sensible parameters.

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