Diagnosis of Thermal Efficiency of Advanced Combined Cycle Power Plants Using Optical Torque Sensor

2005 ◽  
Author(s):  
Shuichi Umezawa
Keyword(s):  
Thermal Efficiency ◽  
Power Plants ◽  
Power Transmission ◽  
Combined Cycle ◽  
Signal Process ◽  
Bar Code ◽  
Sensor Performance ◽  
Power Company ◽  
Optical Torque ◽  
Plant Efficiency

A new optical torque measurement method was applied to diagnosis of thermal efficiency of advanced combined cycle, i.e. ACC, plants. Since the ACC power plant comprises a steam turbine and a gas turbine and both of them are connected to the same generator, it is difficult to identify which turbine in the plant deteriorates the performance when the plant efficiency is reduced. The sensor measures axial distortion caused by power transmission by use of He-Ne laser beams, small stainless steel reflectors having bar-code patterns, and a technique of signal processing featuring high frequency. The sensor was applied to the ACC plants of TOKYO ELECTRIC POWER COMPANY, TEPCO, following the success in the application to the early combined cycle plants of TEPCO. The sensor performance was inspected over a year. After an improvement related to the signal process, it is considered that the sensor performance has reached a practical use level.

Diagnosis of Thermal Efficiency of Nuclear Power Plants Using Optical Torque Sensors

2006 ◽  
Author(s):  
Shuichi Umezawa ◽  
Jun Adachi
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Torsional Rigidity ◽  
Combined Cycle ◽  
Sensor Performance ◽  
Optical Torque

A new optical torque measuring method was applied to diagnosis of thermal efficiency of nuclear power plants. The sensor allows torque deformation of the rotor caused by power transmission to be measured without contact. Semiconductor laser beams and small pieces of stainless reflector that have bar-code patterns are employed. The intensity of the reflected laser beam is measured and then input into a computer through an APD and an A/D converter having high frequency sampling rates. The correlation analysis technique can translate these data into the torque deformation angle. This angle allows us to obtain the turbine output along with the torsional rigidity and the rotating speed of the rotor. The sensor was applied to a nuclear plant of Tokyo Electric Power Company, TEPCO, following its application success to the early combined cycle plants and the advanced combined cycle plants of TEPCO. As the turbine rotor of the nuclear power plant is less exposed than that of the combined cycle plants, the measurement position is confined to a narrow gap. In order to overcome the difficulty in installation, the shape of the sensor is modified to be long and thin. Sensor performance of the nuclear power plant was inspected over a year. The value of the torsional rigidity was analyzed by the finite element method at first. Accuracy was improved by correcting the torsional rigidity so that the value was consistent with the generator output. As a result, it is considered that the sensor performance has reached a practical use level.

Improving Plant Efficiency While Optimizing Water Use in Simple and Combined Cycle Power Plants

2008 ◽  
Author(s):  
Peter G. Demakos
Keyword(s):  
Power Plants ◽  
Closed Loop ◽  
Cost Effective ◽  
Poor Quality ◽  
Combined Cycle ◽  
Cooling Systems ◽  
Scarce Water ◽  
Quality Water ◽  
Poor Quality Water ◽  
Plant Efficiency

Closed-loop, evaporative cooling systems (Wet Surface Air Coolers) are a cost-effective heat transfer technology (for cooling and condensing) in simple and combined cycle power plants that also optimize use of scarce water resources. In addition to providing lower outlet temperatures and requiring less space and horsepower (HP), the WSAC can use poor quality water as spray makeup.

Exergy Evaluation of Two Current Advanced Power Plants: Supercritical Steam Turbine and Combined Cycle

1997 ◽  
Vol 119 (4) ◽  
pp. 250-256 ◽  
Author(s):  
H. Jin ◽  
M. Ishida ◽  
M. Kobayashi ◽  
M. Nunokawa
Keyword(s):  
Steam Turbine ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Power Plants ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Exergy Loss ◽  
Heat Recovery Steam Generator ◽  
Combined Cycle Plant ◽  
Steam Plant

Two operating advanced power plants, a supercritical steam plant and a gas-steam turbine combined cycle, have been analyzed using a methodology of graphical exergy analysis (EUDs). The comparison of two plants, which may provide the detailed information on internal phenomena, points out several inefficient segments in the combined cycle plant: higher exergy loss caused by mixing in the combustor, higher exergy waste from the heat recovery steam generator, and higher exergy loss by inefficiency in the power section, especially in the steam turbine. On the basis of these fundamental features of each plant, we recommend several schemes for improving the thermal efficiency of current advanced power plants.

A Holistic Approach to GTCC Operational Efficiency Improvement Studies

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
Sowande Z. Boksteen ◽  
Jos P. van Buijtenen ◽  
Dick van der Vecht
Keyword(s):  
Power Plants ◽  
Combined Cycle ◽  
Fuel Quality ◽  
Efficiency Improvement ◽  
Ambient Conditions ◽  
Operational Parameters ◽  
Decision Variables ◽  
Wide Range ◽  
Exergy Losses ◽  
Plant Efficiency

Because of the increasing share of renewables in the energy market, part load operation of gas turbine combined cycle (GTCC) power plants has become a major issue. In combination with the variable ambient conditions and fuel quality, load variations cause these plants to be operated across a wide range of conditions and settings. However, efficiency improvement and optimization studies are often focused on single operating points. The current study assesses efficiency improvement possibilities for the KA26 GTCC plant, as recently built in Lelystad, The Netherlands, taking into account that the plant is operated under frequently varying conditions and load settings. In this context, free operational parameters play an important role: these are the process parameters, which can be adjusted by the operator without compromising safety and other operational objectives. The study applies a steady state thermodynamic model with second-law analysis for exploring the entire operational space. A method is presented for revealing correlations between the exergy losses in major system components, indicating component interactions. This is achieved with a set of numerical simulations, in which operational conditions and settings are randomly varied, recording plant efficiency and exergy losses in major components. The resulting data is used to identify distinct operational regimes for the GTCC. Finally, the free operational parameters are used as decision variables in a genetic algorithm, optimizing plant efficiency in the operational regimes identified earlier. The results show that the optimal settings for decision variables depend on the regime of operation.

scholarly journals Thermo-economic Assessment of the first Integrated Solar Combined Cycle System of Hassi R’mel

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 242-251
Author(s):  
M. AMANI ◽  
A. SMAILI ◽  
A. GHENAIET
Keyword(s):  
Thermal Efficiency ◽  
Environmental Effect ◽  
Power Plants ◽  
Economic Assessment ◽  
Combined Cycle ◽  
Electricity Production ◽  
Fuel Saving ◽  
Electricity Cost ◽  
Cycle System ◽  
Solar Electricity

The aim of this study is the thermo-economic assessments of an integrated solar combined cycle (ISCC) system, in terms of thermal efficiency, electricity production and levelized electricity cost (LCOE). During the day light the power plant operates as an ISCC and operates as a conventional combined cycle (CC) during the night or cloudy days. In one hand the obtained results show that at the design point the solar electricity ratio may reach about 17 % and the global thermal efficiency 63 %, leading to lower fuel consumption and carbon emission. On the other hand, the economic assessment depicts that LCOE may reach 0.0222 $/kWh, which is about 28 % higher than that of (CC) power plants. Furthermore, by introducing the environmental effect LCOE becomes equal to 0.0272 $/kWh which is higher. Therefore, the annual solar contribution relatively to this ISCC installation site will allow about 18.45 million $ of fuel saving, avoiding emission of 0.89 million ton of CO2 over 30 years operation.

Assessment of Humid Air Turbines in Coal-Fired High Performance Power Systems

1996 ◽  
Author(s):  
Julianne M. Klara ◽  
Robert M. Enick ◽  
Scott M. Klara ◽  
Lawrence E. Van Bibber
Keyword(s):  
Power Systems ◽  
Thermal Efficiency ◽  
High Performance ◽  
Power Plants ◽  
Combined Cycle ◽  
Humid Air ◽  
Levelized Cost Of Electricity ◽  
Capital Costs ◽  
Air Turbine ◽  
Net Power Output

The purpose of this study is to assess the feasibility of incorporating a Humid Air Turbine (HAT) into a coal-based, indirectly fired High Performance Power System (HIPPS). The HIPPS/HAT power plant exhibits a one percentage point greater thermal efficiency than the combined-cycle HIPPS plant. The capital costs for the HIPPS and HIPPS/HAT plants with identical net power output are nearly equivalent at $1380/kW. Levelized cost of electricity (COE) for the same size plants is 5.3 cents/kWh for the HIPPS plant and 5.4 cents/kWh for the HIPPS/HAT plant; the HIPPS/HAT plant improved thermal efficiency is offset by the higher fuel cost associated with a lower coal/natural gas fuel ratio. However, improved environmental performance is associated with the HIPPS/HAT cycle, as evidenced by lower CO2, SO2, and NOx emissions. Considering the uncertainties associated with the performance and cost estimates of the yet unbuilt components, the HIPPS/HAT and HIPPS power plants are presently considered to be comparable alternatives for future power generation technologies. The Department of Energy’s Combustion 2000 Program will provide revised design specifications and more accurate costs for these components allowing more definitive assessments to be performed.

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