scholarly journals The application of modified thermodynamic system correction method to secondary reheat steam turbine

2022 ◽  
Vol 355 ◽  
pp. 02058
Author(s):  
Tongyang Pan ◽  
Jifan Zhang ◽  
Jiannan Kang ◽  
Mingcheng Li
Keyword(s):  
Steam Turbine ◽  
Maximum Error ◽  
Correction Method ◽  
Thermodynamic System ◽  
Test Accuracy ◽  
Thermal System ◽  
Calculation Step ◽  
Reheat Steam ◽  
Result Analysis ◽  
Correction Result

In order to calculation the enthalpy of wet steam in the secondary reheat turbine thermal system the thermodynamic system of the secondary reheat steam turbine based on the isentropic ideal expansion process line was corrected, This method simplifies the correction calculation step and increases the accuracy of the correction result. Analysis of the rationality of the improved method shows that: Compared with the existing secondary reheat steam turbine thermal system correction method, the maximum error of the improved thermal system correction method is 0.14%. Therefore, this method can better meet the test accuracy requirements.

Repowering and Retrofitting

2002 ◽  
Author(s):  
Andreas Pickard
Keyword(s):  
Steam Turbine ◽  
Power Plants ◽  
Free Market ◽  
Leading Edge ◽  
Project Planning ◽  
Combined Cycle ◽  
Steam Turbines ◽  
Planning Stage ◽  
Reheat Steam ◽  
Plant Optimization

At the start of this new century, environmental regulations and free-market economics are becoming the key drivers for the electricity generating industry. Advances in Gas Turbine (GT) technology, allied with integration and refinement of Heat Recovery Steam Generators (HRSG) and Steam Turbine (ST) plant, have made Combined Cycle installations the most efficient of the new power station types. This potential can also be realized, to equal effect, by adding GT’s and HRSG’s to existing conventional steam power plants in a so-called ‘repowering’ process. This paper presents the economical and environmental considerations of retrofitting the steam turbine within repowering schemes. Changing the thermal cycle parameters of the plant, for example by deletion of the feed heating steambleeds or by modified live and reheat steam conditions to suit the combined cycle process, can result in off-design operation of the existing steam turbine. Retrofitting the steam turbine to match the combined cycle unit can significantly increase the overall cycle efficiency compared to repowering without the ST upgrade. The paper illustrates that repowering, including ST retrofitting, when considered as a whole at the project planning stage, has the potential for greater gain by allowing proper plant optimization. Much of the repowering in the past has been carried out without due regard to the benefits of re-matching the steam turbine. Retrospective ST upgrade of such cases can still give benefit to the plant owner, especially when it is realized that most repowering to date has retained an unmodified steam turbine (that first went into operation some decades before). The old equipment will have suffered deterioration due to aging and the steam path will be to an archaic design of poor efficiency. Retrofitting older generation plant with modern leading-edge steam-path technology has the potential for realizing those substantial advances made over the last 20 to 30 years. Some examples, given in the paper, of successfully retrofitted steam turbines applied in repowered plants will show, by specific solution, the optimization of the economics and benefit to the environment of the converted plant as a whole.

Thermal System Optimization and Energy Grade Analysis of 700°C HUSC Steam Turbine Using a EC System

2018 ◽  
Author(s):  
Haiyu He ◽  
Tao Chen ◽  
Shiwang Fan ◽  
Xiaohua Xia ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Load Condition ◽  
System Optimization ◽  
Thermodynamic System ◽  
Feed Water ◽  
Steam Temperature ◽  
Efficient System ◽  
Cycle System ◽  
System Solution ◽  
Main Steam

700°C High Ultra Supercritical (HUSC) technology is taken into account as a more efficient clean coal-fired power generation technology which can achieve higher efficiency and less CO2 emission. With the increase of the main steam and reheat steam temperature, the temperature of regenerative extraction increased accordingly. This not only means higher investment cost and higher unreliability of power plant, but also leads to a great reduction of energy grade efficiency. To solve the above-mentioned problem, we introduce a novel system, called echelon cycle system (EC system). In EC system, a BEST (Backpressure Extraction Steam Turbine) is added, which provides power for feed-water pump and steam for feed-water heaters. The steam source of high temperature regenerative extractions is switched from main turbine to BEST, and the steam source of BEST is cold-reheat. Hence the highest regenerative extraction steam temperature decreased accordingly. EC system has been demonstrated to be a more efficient system by exergy theory[1] and energy grade theory. Three types of EC system are proposed in this paper. Thermal performance calculation of these three types of EC system under rated-load condition and part-load condition is carried out to evaluate and compare the economy of system. In order to obtain a more appropriate thermodynamic system solution, safety and restriction should also be given sufficient consideration. Meanwhile, the matrix solution method for energy grade efficiency of EC system is derived in this paper. Finally, energy grade theory is used to analyze how different schemes cause different hate rate profits.

Double Phase Differences Correction Method for Frequency and Phase in Spectrum Analysis

2013 ◽  
Vol 584 ◽  
pp. 87-91
Author(s):  
Jiu Fei Luo ◽  
Zhi Jiang Xie ◽  
Ping Chen
Keyword(s):  
Harmonic Signal ◽  
Maximum Error ◽  
Correction Method ◽  
Spectral Lines ◽  
Frequency Resolution ◽  
Two Phase ◽  
Double Phase ◽  
New Formula ◽  
Frequency Phase ◽  
Phase Differences

This paper advances a new method, double phase differences correction method, which aims at correcting the errors of frequency, phase and amplitude of the harmonic signal. The employment of this method involves that two phase differences of two highest spectral lines in the main lob are used to get the correcting value of frequency and then phase and amplitude can be rectified by corresponding formula. It solves the problem that the traditional formula of translation of window center is only for rectangle window. This new formula can correct for the different window by the principle of translation of window center. Simulation shows that the maximum error of frequency of the signal with white noise is less than 1% of frequency resolution. The maximum error of phase is around 1.5º, and the maximum error of amplitude is within 0.01. The average errors in frequency, phase and amplitude are approximately 0.002Hz, 1º and 0.005, respectively.

Study on Dynamic Phase Correction Method for Improving the Test Accuracy of the Pneumatic Shape Measuring Roll

2013 ◽  
Vol 457-458 ◽  
pp. 1334-1337
Author(s):  
Xu Guang Sun ◽  
Chang Hai Wang ◽  
Shi Yan Shan ◽  
Cheng Long Feng
Keyword(s):  
Correction Method ◽  
Phase Correction ◽  
Differential Pressure ◽  
Dynamic State ◽  
Test Accuracy ◽  
Dynamic Phase ◽  
Testing Accuracy

In brief introduction of the pneumatic shape measuring roller's construction and work principle, the static and dynamic state experiments of the roller then found distributing regulation and characteristics of the measuring differential pressure which following circumference direction. Then we put forward dynamic phase correction method to improve the testing accuracy of the roller. It passes by experimentation to prove the possibility of method in this text.

Thermo-Economic Analysis of the Ultra-Supercritical 900 MW Power Unit With the Various Configurations of the Auxiliary Steam Turbine

2012 ◽  
Author(s):  
Katarzyna Stępczyńska ◽  
Henryk Łukowicz ◽  
Sławomir Dykas ◽  
Sebastian Rulik
Keyword(s):  
Economic Analysis ◽  
Steam Turbine ◽  
Co2 Emissions ◽  
Power Unit ◽  
Mass Flow ◽  
Feed Water ◽  
Feed Pump ◽  
Water Heaters ◽  
Reheat Steam ◽  
Steam Parameters

Coal-based electric power generation remains the basic source of obtaining energy. With increasing pressure to reduce CO2 emissions, improving power unit efficiency has become an issue of utmost significance. The development of technologies related to coal-fired power units does not focus solely on the steam parameters ahead of the turbine. Increasing the live steam parameters usually constitutes the greatest contribution to the rise in the efficiency of a power unit, but the sum of efficiency gains related to the application of other solutions can also be significant and can, in some cases, exceed the effects related to raising the temperature and steam pressure values. A paper presents thermodynamic and economic analysis of various configurations of the ultra-supercritical coal-fired 900 MW power unit with the auxiliary steam turbine. Main subject of research was a power unit considered within the Strategic Research Programme – Advanced Technologies for Energy Generation with the parameters of live and reheat steam: 30 MPa/650°C/670°C. The base configuration of the power unit has single steam reheat and electric drive boiler feed pump. Analysis of ultra-supercritical 900 MW power unit involves configuration with a single and double reheat. The following configurations of the auxiliary steam turbine will be presented and compared: • extraction-backpressure steam turbine fed with steam from cold reheat line with bleed and steam outlet directed to the feed water heaters; • extraction-backpressure steam turbine fed with steam from cold reheat line with bleed and steam outlet directed to the feed water heaters; the auxiliary turbine drives the boiler feed pump; • backpressure turbine fed with steam from a hot reheat steam line operating in parallel with the intermediate-pressure turbine; the auxiliary turbine drives the boiler feed pump. The analysis of the operation of the 900 MW unit was carried out for three load levels: for the nominal mass flow of live steam, and for the partial mass flow of 75% and 50%. For all presented solutions thermodynamic and economic analysis was performed, which has taken into account the charge for CO2 emissions.

The Combined Reheat Gas Turbine/Steam Turbine Cycle: Part II—The LM 5000 Gas Generator Applied to the Combined Reheat Gas Turbine/Steam Turbine Cycle

1980 ◽  
Vol 102 (1) ◽  
pp. 42-49 ◽  
Author(s):  
I. G. Rice
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Heat Recovery Boiler ◽  
Gas Generator ◽  
Reheat Steam ◽  
Cycle Efficiency ◽  
Minimum Heat ◽  
Steam Heat

Part I presented an analysis of the simple and reheat gas turbine cycles and related these cycles to the combined gas turbine Rankine cycle. Part II uses the data developed in Part I and applies the second generation LM5000 to a combined cycle using a steam cycle with 1250 psig 900 FTT (8.62MPa and 482°C) steam conditions; then the reheat gas turbine is combined with a reheat steam turbine with steam conditions of 2400 psig and 1000/1000 FTT (16.55 MPa and 538/538° C). A unique arrangement of the superheater is discussed whereby part of the steam heat load is shifted to the reheat gas turbine to obtain a minimum heat recovery boiler stack temperature and a maximum cycle efficiency. This proposed power plant is projected to have a net cycle efficiency of 50 percent LHV when burning distillate fuel.

An Integrated Steam/Gas Turbine-Generator for Combined-Cycle Applications

1989 ◽  
Author(s):  
J. H. Moore
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Gas Temperature ◽  
Turbine Generator ◽  
Fully Integrated ◽  
Reheat Steam ◽  
Exhaust Gas Temperature ◽  
Steam Cycle

Combined-cycle power plants have been built with the gas turbine, steam turbine, and generator connected end-to-end to form a machine having a single shaft. To date, these plants have utilized a nonreheat steam cycle and a single-casing steam turbine of conventional design, connected to the collector end of the generator through a flexible shaft coupling. A new design has been developed for application of an advanced gas turbine of higher rating and higher firing temperature and exhaust gas temperature with a reheat steam cycle. The gas turbine and steam turbine are fully integrated mechanically, with solid shaft couplings and a common thrust bearing. This paper describes the new machine, with emphasis on the steam turbine section where the elimination of the flexible coupling created a number of unusual design requirements. Significant benefits in reduced cost and reduced complexity of design, operation, and maintenance are achieved as a result of the integration of the machine and its control and auxiliary systems.

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